kereta api semboyan

Kalau kita sering naek kereta api baik kereta ekonomi sampai kelas eksekutif mungkin sering sekilas kita melihat tulisan seperti K3-67514 atau K2-86501 tulisan ini biasanya kita temukan di luar gerbong atau di dalam gerbong tepat di atas pintu keluar menuju bordes nah apa si arti kode itu, nah ini jawabannya tolong dikoreksi kalau salah : Gerbong kereta api milik PT Kereta Api (Persero) dibedakan menjadi beberapa jenis yaitu kereta/gerbong penumpang kelas Ekonomi, Bisnis, Eksekutif. kemudian Kereta/gerbong makan kelas Ekonomi, Bisnis, Eksekutif. dan Kereta Pembangkit atau Kereta Bagasi. nah kode sebelum tanda ‘-’ itu menunjukkan jenis gerbong contoh : K1 : Gerbong kelas Eksekutif KM1 : Gerbong Makan kelas Eksekutif K2 : Gerbong kelas Bisnis KM2 : Gerbong Makan kelas Bisnis K3 : Gerbong kelas Ekonomi KM3 : Gerbong Makan kelas Ekonomi KMP : Gerbong Makan Pembangkit (Jenis Kereta Makan + Pembangkit Mini) biasanya hanya untuk kelas Ekonomi dan Bisnis (KMP3 & KMP2) KP : Gerbong Pembangkit Listrik BP : Gerbong Bagasi Penumpang kemudian 2 digit setelah tanda ‘-’ menunjukkan tahun pembuatan gerbong contoh : K1-67xxx berarti gerbong kelas Eksekutif tahun pembuatan gerbong 1967 kemudian 1 digit setelah tahun pembuatan menunjukkan kode seri boogie ( Rangkaian Roda Kereta ) setiap seri menunjukkan karakteristik dari beban dan batas kecepatan pacu gerbong , yang saya tahu ada 5 jenis seri yaitu seri 5,6,7,8,9 yang batas kecepatan nya berkisar antara 80km/h – 120 Km/h Ciri Ciri Boogie seri : 5 : 1 Boogie 4 roda ditiap tiap roda mengunakan per keong , termasuk per utamanya dengan mak kecepatan 100 km/h . 6 : 1 Boogie 4 roda ditiap roda menggunakan per keong , per utama menggunakan per daun dengan mak kecepatan 100 km/h . 7 : 1 Boogie 4 roda ditiap roda menggunakan per daun, termasuk per utamanya dengan mak kecepatan 100 km/h . 8 : 1 Boogie 4 roda ditiap roda menggunakan suspensi pegas karet, suspensi sekunder menggunakan per keong dengan mak kecepatan 120 km/h . 9 : 1 Boogie 4 roda ditiap roda menggunakan suspensi pegas karet, suspensi sekunder menggunakan pegas udara dengan mak kecepatan 120 km/h . contoh : K2-xx5xx berarti kereta Bisnis yang menggunakan boogie seri 5 yang mampu melaju sampai kecepatan 100 km/h . seri 5,6,7 biasanaya digunakan untuk gerbong seri lama dengan tahun pembuatan 60,70,80 seri 8 untuk tahun 90 an untuk kelas Argo Generasi 1 ( Argo Bromo ) namun karena dirasakan kurang nyaman oleh penumpang banyak yang di ganti dengan seri 5 yang dianggap lebih stabil seri 9 digunakan kereta Argo terbaru seperti Argo Anggrek yang sekarang gerbongnya berwarna pink dan bentuknya seperti trapesium. 2 digit terakhir menunjukkan nomor inventaris biasanya dari nomor 1 sampek sebanyak gerbong yang dimiliki oleh PT Kereta Api (Persero) sesuai kelasnya . contoh K1-02901 berarti gerbong kelas Eksekutif pertama milik PT Kereta Api (Persero) yang di buat tahun 2002.

rail wessel

Railroad switch

A right-hand railroad switch.

Animated diagram of a right-hand railroad switch showing principle of operation.

This article primarily uses North American terminology. British and Commonwealth terms are given in brackets.

A railroad switch is a mechanical installation enabling trains to be guided from one track to another. In the UK and Commonwealth countries, railroad switches are known as (sets of) points. In technical usage switches are also called turnouts.

In the diagram on the right, rail track A divides into two: track B (the straight track) and track C (the diverging track). The switch consists of the pair of linked tapering rails, known as points (switch rails or point blades), lying between the diverging outer rails (the stock rails). These points can be moved laterally into one of two positions so as to determine whether a train coming from A will be led towards B or towards C. A train moving from the A direction towards either B or C is said to be executing a facing-point movement.

Unless the switch is locked, a train coming from B or C will be led to A regardless of the position of the points, as the vehicle’s wheels will force the points to move. Passage through a switch in this direction is known as a trailing-point movement.

A switch can be described by the direction in which the diverging track leaves the straight track. A right-hand switch has track C to the right of a straight track formed by A and B. A left-hand switch has track C to the left.

A straight track is not always present; for example, both tracks may curve, one to the left and one to the right (see Wye switch, below) or both tracks may curve, with differing radii, in the same direction.

Contents [hide] 1 Operation 1.1 High-speed operation 1.2 Operation in cold conditions 1.3 Tram and monorail systems 1.4 Roller coaster switches 2 Classification 3 Safety 4 History 5 Components 5.1 Points (point blades) 5.2 Frog (common crossing) 5.3 Guard rail (check rail) 5.4 Switch motor 5.5 Points lever 5.6 Joints 5.7 Components gallery 6 Types of switches 6.1 Double slip 6.2 Single slip 6.3 Outside slip 6.4 Crossover 6.5 Stub switch 6.6 Plate switch 6.7 Three-way switch 6.8 Interlaced turnout 6.9 Wye switch 6.10 Run-off points 6.10.1 Derailers 6.11 Dual gauge switches 6.12 Switch diamond 7 References 8 See also 9 External links

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[edit] Operation

The operation of a railroad switch. In this animation, the red track is the one travelled during a facing-point movement. The switch mechanism, shown in black, may be operated remotely using an electric motor or lever or from a nearby ground frame.

A railroad car’s wheels are guided along the tracks by coning of the wheels. Only in extreme cases does it rely on the flanges located on the insides of the wheels. When the wheels reach the switch, the wheels are guided along the route determined by which of the two points is connected to the track facing the switch. In the illustration, if the left point is connected, the left wheel will be guided along the rail of that point, and the train will diverge to the right. If the right point is connected, the right wheel’s flange will be guided along the rail of that point, and the train will continue along the straight track. Only one of the points may be connected to the facing track at any time; the two points are mechanically locked together to ensure that this is always the case.

A mechanism is provided to move the points from one position to the other (change the points). Historically, this would require a lever to be moved by a human operator, and some switches are still controlled in this way. However, most are now operated by a remotely controlled electric motor or by pneumatic or hydraulic actuation.

In a trailing-point movement, the wheels will force the points to the proper position. This is sometimes known as running through the switch. If the points are rigidly connected to the switch control mechanism, the control mechanism’s linkages may be bent, requiring repair before the switch is again usable. For this reason, switches are normally set to the proper position before performing a trailing-point movement. ^[1].

An example of mechanism that would require repair after a run-through in the trailing direction is a clamp-lock. This mechanism is popular in the UK, but the damage caused is common to most types of switches. However, some switches are designed to be forced to the proper position without damage. Examples include variable switches, spring switches, and weighted switches.

[edit] High-speed operation

Generally, switches are designed to be safely traversed at low speed. However, it is possible to modify the more simple types of switch to allow trains to pass at high speed. More complicated switch systems, such as double slips are restricted to low-speed operation.

The conventional way to increase turnout speeds is to lengthen the turnout and use a shallower frog angle. If the frog angle is so shallow that a fixed frog cannot support a train’s wheels, a swingnose crossing (US: moveable point frog) will be used. Higher speeds are possible without lengthening the turnout by using uniformly curved rail and a very low entry angle.

An AREMA (American Railway Engineering and Maintenance of Way Association) design number 20 turnout has a diverging speed limit of 45 miles per hour. ^[2][3]

[edit] Operation in cold conditions

Gas heating keeps a switch free from snow and ice.

In cold conditions, snow and ice can prevent the correct operation of switches. In the past, people were employed by railway companies to keep the switches clear by sweeping the snow away, and this is still used in some countries, especially on minor lines. Some were provided with gas torches for melting ice. More recently, switches have had heaters installed in the vicinity of the points so that the temperature of the rails in these areas can be kept above freezing. The heaters may be powered by gas or electricity.

[edit] Tram and monorail systems

A switch on the Listowel and Ballybunion Railway, Ireland, in 1912

The switch points of tram lines are often operated remotely by the driver. Monorail systems have special switches.

[edit] Roller coaster switches

Many roller coasters have switches for the siding, or even for a double station system, for example in Disneyland Resort Paris‘ Space Mountain and Big Thunder Mountain coasters.

Regular rail can cross its own track because the gaps in the rails for wheel flanges are narrow, permitting the bladed design in this article. Round pipe roller coaster rails and box beam monorail rails usually have wheels riding at angles other than on top. These additional other angle wheels are a larger loading gauge, requiring big gaps in the rail (structure gauge) where rails cross or meet.

There are three basic switch designs for roller coasters. Flexing, substituting and table rotating rails have all been used. Flexing the entire rail truss, fixed at one end, to point towards an alternate destination requires manipulating a long segment of rail. Substituting a segment requires placing two or more segments of rail on flat plate that is moved in its entirety to provide straight or curved track.

Substitution track switch for rail at Chester Zoo

Alternately these substitution track segments can be wrapped around a rotating cylinder, creating a triangular truss or a two sided plate. Rotating a table with a curved track segment in a Y junction is the less used third option. This can even make a triangle junction. If the curved track turns the cars 60 degrees, and three rail lines meet as three equally spaced spokes, 120 degrees apart, than the curved track sitting on a turn table can be rotated to connect any two of the three rail lines at this junction.

[edit] Classification

The divergence and length of a switch is determined by the angle of the frog (the point in the switch where two rails cross, see below) and the curvature of the switch blades. The length and placement of the other components are determined from this using established formulas and standards. This divergence is measured as the number of units of length for a single unit of separation.

In North America this is generally referred to as a switch’s “number”. For example, on a “number 12″ switch, the rails are one unit apart at a distance of twelve units from the center of the frog. In the United Kingdom points and crossings using chaired bullhead rail would be referred to using a letter and number combination. The letter would define the length (and hence the radius) of the switch blades and the number would define the angle of the crossing (frog). Thus an A7 turnout would be very short and likely only to be found in dockyards etc. whereas an E12 would be found as a fairly high speed turnout on a mainline.

[edit] Safety

The correct setting of points is fundamental to the safe running of a railway. For example, an incorrectly set switch may result in two trains being on the same track, causing a collision.

Perhaps the greatest security challenge in railway operation is preventing the tampering of manually-operable switches. Similar (non-fatal) wrecks near Newport News, Virginia on August 12, 1992 and in Stewiacke, Nova Scotia on April 12, 2001 resulted from switches being thrown open in front of the trains by teenaged saboteurs. To prevent these incidents, most unused switches are locked up.

In 1980, 18 people died in the Buttevant Rail Disaster at Buttevant, Co. Cork in Ireland, when the Dublin-Cork express was derailed at high speed after being inadvertently switched into a siding via ground frame operated points.

The Potters Bar rail crash at Potters Bar, Hertfordshire in the United Kingdom occurred in May 2002, when a switch sprang to a different position as a coach crossed it, a type of mishap called “splitting the switch.” The front wheels of a coach progressed along the straight track as intended, but the rear wheels slewed along the diverging track. This caused the whole coach to detach from the train and slew sideways across the platform ahead. Fortunately, the movement of the switch occurred beneath the final coach, so that although 7 people were killed, the front coaches remained on the tracks. Poor maintenance of the points was found to be the primary cause of the crash. The initial conclusion of the enquiry into the Grayrigg derailment of 23 February 2007 blames an incorrectly maintained set of points.

[edit] History

On early lines, vehicles were moved between tracks by means of sliding rails. The switch as we know it was patented by Charles Fox in 1832.

Prior to the widespread availability of electricity, switches at heavily-traveled junctions were operated from a signal box constructed near the tracks through an elaborate system of rods and levers. The levers were also used to control railway signals to control the movement of trains over the points. Eventually, mechanical systems known as interlockings were introduced to make sure that a signal could only be set to allow a train to proceed over points when it was safe to do so. On some low-traffic branch lines, in self-contained marshalling yards, or on heritage railways, switches may still be operated in this way.

[edit] Components

[edit] Points (point blades)

The points (switch rails or point blades) are the movable rails which guide the wheels towards either the straight or the diverging track. They are tapered on most switches, but on stub switches they have square ends.

In the UK and Commonwealth countries, the term points refers to the entire mechanism, whereas in North America the term refers only to the movable rails.

[edit] Frog (common crossing)

The frog (common crossing) refers to the crossing point of two rails. This can be assembled out of several appropriately cut and bent pieces of rail or can be a single casting. A frog forms part of a railroad switch, and is also used in a level junction (flat crossing). The frog is a point of weakness because the wheels are unsupported for a short distance and can inflict wear and damage. There is also a small risk that the wheels may go the wrong way.^{[citation needed]}

On lines with heavy and/or high-speed traffic, a swingnose crossing is often used. As the name implies, there is a second set of points located at the frog. This effectively eliminates the gap in the rail that normally occurs at the frog, so long as trains are moving in the direction that the switch is aligned to. Two switch machines are required to make a movable point frog switch work.

This use of the word “frog” derives from the appearance of the triangular assemblage of rails which recalls the frog of a horse’s hoof.

[edit] Guard rail (check rail)

A guard rail (check rail) is a short piece of rail placed alongside the main (stock) rail opposite the frog. These exist to ensure that the wheels follow the appropriate flangeway through the frog and that the train does not derail. Generally, there are two of these for each frog, one by each outer rail. Guard rails are not required with a “self-guarding cast manganese” frog, as the raised part of the casting serve the same purpose. These frogs are for low-speed use and are common in rail yards.

[edit] Switch motor

A switch motor (also known as a switch machine or point machine) is an electric or hydraulic or pneumatic mechanism that aligns the points with one of the possible routes. The switch motor also includes electrical contacts to detect that the switch has completely set and locked. If the switch fails to do this, signals are kept at red.

[edit] Points lever

A points lever, ground throw, or switchstand is a lever and accompanying linkages that are used to align the points of a switch manually. This lever and its accompanying hardware is usually mounted to a pair of long sleepers that extend from the switch at the points. They are often used in a place of a switch motor on infrequently used switches. In some places, infrequently used points may be operated from a ground frame. To prevent the tampering with of these switches by outside means, these switches are locked up when not in use.

[edit] Joints

Joints are used where the moving points meet the fixed rails of the switch. They allow the points to hinge easily between their positions. Originally the movable switch blades were connected to the fixed closure rails with loose joints, but since steel rails are somewhat flexible it is possible to make this join by thinning a short section of the rail itself. This can be called a heelless switch.

[edit] Components gallery

This detail of a switch shows the pair of tapered moveable rails known as the switch points (switch rails or point blades).	A one-piece cast frog. The shiny line crosses the rusty line. This is an example of North American “self-guarding cast manganese” frog, where guard rails are not used, the raised flanges on the frog bearing on the face of the wheel as it passes through the frog.	The frog (left) and guard rail (right) can be seen in this detail of a switch.	Several different styles of switch stand on display
The mechanism used at a switch. The two points are locked together with a bar between them. This bar continues to the lever on the near side of the tracks which is used to throw the switch. This is an example of a low switch stand, used at locations where there is not sufficient clearance for a tall switch stand. This particular stand is designed to be trailed through by rolling stock, which will cause the points to become lined for the route that the wheels have passed through. It has a reflectorised target.	A swingnose crossing. The point of the V-shaped rail is moved to align the rail in the appropriate direction where the two rails cross.	The switch motor (in this case an electric motor) and associated mechanism used to operate this switch can be seen to the right of the picture.	A ground frame (at Bristol Temple Meads station, UK) contains a few levers for manually operating nearby points.
The construction of a light industrial or yard track switch joint, where the points are joined to the closure rails by bolts through a “joint bar” or (“fish plates”).

[edit] Types of switches

A double switch, or double slip.

Apart from the standard right-hand and left-hand switches, switches commonly come in various combinations of configurations.

[edit] Double slip

A double slip switch (double slip) is a narrow-angled diagonal flat crossing of two lines combined with four pairs of points in such a way as to allow vehicles to change from one straight track to the other, as well as going straight across. A train approaching the arrangement may leave by either of the two tracks on the opposite side of the crossing. To reach the third possible exit, the train must change tracks on the slip and then reverse.

The arrangement gives the possibility of setting four routes, but the four blades at each end of the crossing are often connected to move in unison, so the crossing can be worked by just two levers or point motors.

In North America, the arrangement may also be called a double switch, or more colloquially, a puzzle switch. The Great Western Railway in the United Kingdom used the term double compound points, and the switch is also known as a double compound in Victoria (Australia).

[edit] Single slip

Outside slip in Heidelberg main station

A single slip switch works on the same principle as a double slip but provides for only one switching possibility. Trains approaching on one of the two crossing tracks can either continue over the crossing, or switch tracks to the other line. However, trains from the other track can only continue over the crossing, and cannot switch tracks. This is normally used to allow access to sidings and improve safety by avoiding having switch blades facing the usual direction of traffic.

[edit] Outside slip

An outside slip switch is similar to both the double and single slips, but the switch blades are not contained wholly within the diamond. A semi-outside slip is one where the switch blades are partly contained within the diamond. A fully-outside switch is one where the switch blades do not enter the diamond.

[edit] Crossover

A scissors crossover: two pairs of switches linking two tracks to each other in both directions.

A crossover is a pair of switches that connects two parallel rail tracks, allowing a train on one track to cross over to the other. Like the switches themselves, crossovers can be described as either facing or trailing.

When two crossovers are present in opposite directions, one after the other, the four-switch configuration is called a double crossover. If the crossovers overlap it is dubbed a scissors crossover, scissors crossing, or just scissors; or, due to the diamond in the center, a diamond crossover. This makes for a very compact track layout at the expense of using a level junction.

In a setup where each of the two tracks normally carries trains of only one direction, a crossover can be used either to detour “wrong-rail” around an obstruction or to reverse direction. A crossover can also join two tracks of the same direction, possibly a pair of local and express tracks, and allow trains to switch from one to the other.

On a crowded system, routine use of crossovers (or switches in general) will reduce throughput, as the switches must be changed for each train. For this reason, on some high-capacity rapid transit systems, crossovers between local and express tracks are not used during normal rush hour service, and service patterns are planned around use of the usually flying junctions at each end of the local-express line.

[edit] Stub switch

A narrow gauge stub switch.

A stub switch lacks the tapered points (point blades) of a typical switch. Instead, both the movable rails and the ends of the rails of the diverging routes have their ends cut off square. The switch mechanism aligns the movable rails with the rails of one of the diverging routes.

The rails leading up to a stub switch are not secured to the sleepers for several feet, and rail alignment across the gap is not positively enforced. Stub switches also require some flexibility in the rails, or an extra joint at which they hinge. Therefore these switches cannot be traversed at high speed or by heavy traffic and so are not suitable for main line use. A further disadvantage is that a stub switch being approached from the diverging route that is not connected by the points would result in a derailment.

Stub switches were more common in the very early days of railways and their tramway predecessors. Now, because of their disadvantages, stub switches are used primarily on narrow gauge lines and branch lines. Some modern monorail switches use the same principle.

[edit] Plate switch

A narrow gauge plate switch

A plate switch incorporates the tapered points of a typical switch into a self-contained plate. Each point blade is moved separately by hand. Plate switches are only used for double-flanged wheels, with wheels running through the plates on their flanges, guided by the edges of the plate and the moveable blade.

Because plate switches can only be used by double-flanged wheels and at extremely low speeds, they are typically only found on hand-worked narrow gauge lines.

[edit] Three-way switch

A three-way stub switch at Sheepscot station on the Wiscasset, Waterville and Farmington Railway

A three-way switch is used to split a railroad track into three divergent paths rather than the more usual two. The complexity of such arrangements usually results in severe speed restrictions, and therefore three-way switches are usually only used in a station or depot where space is restricted and low speeds are normal.

Stub switches can more readily select between three routes, so most three-way switches are stub switches, although some were built using points.[1] It was extremely difficult to hold the two rails the correct distance apart for the length of the switch with these types of switch.

A three-way switch formerly at Brisbane’s Light Street tram depot now on display at the Brisbane Tramway Museum.

A three-way switch from a Brisbane tram depot is shown on the right. This example has two points (point blades) on each track, allowing for three diverging routes. The points can both be set to one side, resulting in a vehicle turning off the straight track. Alternatively, the two blades can be separated if the vehicle must continue along the straight track.

[edit] Interlaced turnout

A pair of interlaced turnouts on the Loop in Chicago.

An interlaced turnout is a different method of splitting a track into three divergent paths. It is an arrangement of two standard turnouts, one left- and one right-handed, in an “interlaced” fashion. The points of the second turnout are positioned between the points and the frog of the first turnout. In common with other forms of three way turnouts an additional common-crossing is required. Due to the inherent complexity of the arrangement, interlaced turnouts are normally only used in locations where space is exceptionally tight, such as station throats or industrial areas within large cities. Interlaced turnouts can also be found in some yards, where a series of switches branching off to the same side are placed so close together that the points of one switch are placed before the frog of the preceding switch. (example)

[edit] Wye switch

A wye switch.

A wye switch (Y points) has trailing ends which diverge symmetrically and in opposite directions. The name originates from the similarity of their shape to that of the letter Y. Wye switches are usually used where space is at a premium. In North America this is also called an “Equilateral Switch” or “Equilateral Turnout”

[edit] Run-off points

Main article: Catch points

Trap points at the exit from a yard

Run-off points are used to protect main lines from stray or runaway railroad cars or from trains passing signals set at danger. In these cases, vehicles would otherwise roll onto and obstruct a main line (sometimes known as fouling) and cause an accident. Depending on the situation in which they are used, run-off points are referred to either as trap points or catch points. Derailers are another device used for the same purpose.

Catch points are installed on the running line itself, where the railway climbs at a steep gradient. They are used to prevent runaway vehicles colliding with a train or other equipment (such as level crossing barriers) further down the slope. In some cases, catch points lead into a sand drag to safely stop the runaway vehicle, which may be travelling at some speed. Catch points are usually held in the ‘derail’ position by a spring. They can be set to allow a train to pass safely in the downhill direction using a lever or other mechanism to override the spring for a short time.

Catch points originate from the days of the ‘unfitted’ goods train. These trains did not have a mechanism in place to automatically brake runaway cars. Catch points were therefore required to stop the rear portion of a train that had become divided, although they would also stop vehicles that had run away for any other reason. Now that trains are all ‘fitted’, catch points are mostly obsolete.

Similar to catch points, trap points are provided at the exit from a siding or where a goods line joins a line that may be used by passenger trains. Unless they have been specifically set to allow traffic to pass onto the main line, the trap points will direct any approaching vehicle away from the main line. This may simply result in the vehicle being derailed, but in some cases a sand drag is used, especially where the vehicle is likely to be a runaway travelling at speed due to a slope.

[edit] Derailers

Main article: Derail (railroad)

A derailer works by derailing any vehicle passing over it. There are different types of derailer, but in some cases they consist of a single switch point installed in a track. The point can be pulled into a position to derail any equipment that is not supposed to pass.

[edit] Dual gauge switches

A dual gauge switch in Japan.

Dual gauge switches are used in dual gauge systems. There are various possible scenarios involving the routes that trains on each gauge may take, including the two gauges separating or one gauge being able to choose between diverging paths and the other not. Because of the extra track involved, dual gauge switches have more points and frogs than their single gauge counterparts. This limits speeds even more than usual.

[edit] Switch diamond

A switch diamond at a junction in the UK

Although not strictly speaking a turnout, a switch diamond is an active trackwork assembly used where the crossing angle between two tracks is too shallow for totally passive trackwork. These vaguely resemble two standard points assembled very closely toe-to-toe. These would also often utilise swingnose crossings at the outer ends to ensure complete wheel support in the same way as provided

KRD ELEKTRIK

Kereta Rel Diesel Elektrik

(KRDE) merupakan suatu bentuk Transportasi Cepat Massal (MRT, mass rapid transport) yang memadukan mesin diesel dengan teknologi yang dipakai pada Kereta Rel Listrik.

Pada Kereta Rel Diesel yang menggunakan konstruksi hidrolik, mesin diesel (yang terletak di bagian bawah casis) berhubungan langsung dengan penggerak roda secara mekanik. sistem ini memiliki beberapa keuntungan, diantaranya adalah dapat menerobos rel yang tergenang banjir, dan tidak membutuhkan perawatan secara elektris. namun kereta ini memiliki kekurangan, yaitu getaran lebih besar dan lebih bising dari KRL atau KRDE, karena pada KRD satu mesin hanya dapat digunakan untuk satu railcar(gerbong) Pada KRDE, mesin diesel dipakai sebagai pembangkit tenaga listrik (generator). energi listrik yang dihasilkan diolah lagi pada VVVF (variable voltage variable frekuensi)inverter, yaitu suatu rangkaian yang dapat mengubah frekuensi dan tegangan listrik, yang digunakan sebagai kontrol motor induksi. Selanjutnya, output tegangan yang dihasilkan dialirkan ke traction motor (TM) yang ada pada roda. satu TM hanya menggerakan satu roda. jadi dalam satu railcar terdapat empat TM. Jumlah TM yang ada pada satu set KRDE tergantung dari besarnya daya listrik yang dihasilkan generator. keuntungan dari sistem ini antara lain mesin diesel yang terpusat, getaran yang dihasilkan cukup kecil, tidak begitu bising, dan tarikan (akselerasi) lebih besar (3,7 m/s²).

Tragedi Bintaro

Tragedi Bintaro adalah peristiwa tabrakan hebat dua buah kereta api di daerah Pondok Bitung Bintaro, Tangerang, pada tanggal 19 Oktober 1987.

Sebuah kereta api yang berangkat dari Rangkasbitung, bertabrakan dengan kereta api yang berangkat dari stasiun Tanah Abang. Musibah di pagi hari itu menewaskan 139 orang dan mengakibatkan lebih dari 300 orang luka-luka. Peristiwa ini tercatat sebagai salah satu musibah paling buruk dalam sejarah transportasi di Indonesia.

Penyelidikan setelah kejadian menunjukkan adanya kelalaian petugas stasiun Sudimara yang memberikan sinyal aman bagi kereta api dari arah Rangkasbitung padahal tidak ada pernyataan aman dari stasiun Kebayoran.

Permulaan Peristiwa

Peristiwa bermula ketika KRD no.KA 225,jurusan Rangkasbitung-Jakarta Kota tiba di Stasiun Sudimara pada pukul 6:45 WIB. Selang 5 menit kemudian, Jamhari,(petugas PPKA sta. Sudimara) menerima telepon dari Umrihadi (Petugas PPKA sta. Kebayoran Lama) yang mengabarkan KA no.220 jurusan Tanahabang-Merak sudah berangkat menuju Sudimara. Jamhari pun lantas memerintahkan masinis KRD no.225 yang berada di jalur 3 dilansir ke Jalur 1.

Kecelakaan

Tak ayal 2 KA yang sama-sama sarat penumpang, Senin pagi itu bertabrakan di lokasi Km 18.75. Kedua bodi kereta hancur,terguling dan ringsek.Ke-2 lokomotif seri BB 303 16 dan BB 306 16,rusak berat.Ratusan nyawa melayang,dan ratusan penumpang lainnya luka-luka.

Arti Nomor Lokomotif Diesel

Arti Nomor Lokomotif Diesel

Buat penggila kereta maupun temen temen yang sering naek kereta api, sering kita melihat gerbong kereta yang kita naiki di tarik oleh lokomotif yang bentuknya kadang berbeda beda , atau ketika melihat lokomotif langsir di stasiun, sering kita membedakannya kadang hanya dari warnanya namun sebenarnya lokomotif itu juga memiliki nomor KTP seperti halnya kita warga negara indonesia, yaitu nomor lokomotif seperti BB 30101, CC 20340, D 30128 , nah penomoran lokomotif terutama lokomotif diesel di indonesia adalah sebagai berikut :

• kode B artinya 2 roda penggerak ,C = 3 , dan D = 4. jadi kode BB artinya lokomotif bergandar 2 2 jadi total penggeraknya ada 4 as roda atau memiliki 8 roda .
• kode CC artinya lokomotif bergandar 3 3 jadi total penggeraknya ada 6 as roda atau memiliki 12 roda .
• kode D artinya lokomotif bergandar 4 loko jenis ini biasanya hanya memiliki single gandar sehingga total penggeraknya ada 4 as roda dengan jumlah roda 8

Kemudian setelah kode seri ada Kodefikasi 1,2,dan 3

• nomor 1 artinya transmisi Diesel mekanik (tahan banjir, karena transmisi spt mobil, lori dll.)
• nomor 2 artinya transmisi Diesel elektrik (no flad, takut banjir)
• nomor 3 artinya transmisi Diesel hidrolik (tahan banjir)

artinya Diesel elektrik adalah Diesel hanya sebagai pembangkit listrik, kemudian listriknya buat menjalankan motor listrik alias traksi motor karena traksi motor letaknya di bawah menyatu dengan rangkaian as roda maka kalau kena air jelas akan konslet atau rusak , kalau Diesel Hidrolik artinya penggeraknya diesel kemudian diteruskan dengan gardan ke roda2nya,

2 Digit setelah kodefikasi adalah perbedaan fitur fitur yang dimiliki lokomotif biasanya dari kode 00,02,03,04 dst Contoh

• BB200, BB 201, BB 203, BB 205 ,CC 201, CC 202, CC 203, CC 204 bertransmisi elektrik yg takut air
• C 300, D 300, D 301, BB 300, BB 301, BB 302, BB 304, BB 305, BB 306 bertransmisi hidrolik yang berani nerjang banjir

Digit digit berikutnya menandakan nomor inventaris sesuai serinya.
Galery :

D 30128

BB 30003

BB 30330

BB 20205

BB 20029

CC 20411

CC 20340

CC 20216

CC 20198

CC 20015

Sejarah Kereta Api

Sejarah

Sejarah perkeretaapian sama seperti sejarah alat transportasi umumnya yang diawali dengan penemuan roda. Mulanya dikenal kereta kuda yang hanya terdiri dari satu kereta (rangkaian), kemudian dibuatlah kereta kuda yang menarik lebih dari satu rangkaian serta berjalan di jalur tertentu yang terbuat dari besi (rel) dan dinamakan trem. Ini digunakan khususnya di daerah pertambangan tempat terdapat lori yang dirangkaikan dan ditarik dengan tenaga kuda.

Setelah James Watt menemukan mesin uap, Nicolas Cugnot membuat kendaraan beroda tiga berbahan bakar uap. Orang-orang menyebut kendaraan itu sebagai kuda besi. Kemudian Richard Trevithick membuat mesin lokomotif yang dirangkaikan dengan kereta dan memanfaatkannya pada pertunjukan di depan masyarakat umum. George Stephenson menyempurnakan lokomotif yang memenangi perlombaan balap lokomotif dan digunakan di jalur Liverpool-Manchester. Waktu itu lokomotif uap yang digunakan berkonstruksi belalang. Penyempurnaan demi penyempurnaan dilakukan untuk mendapatkan lokomotif uap yang lebih efektif, berdaya besar, dan mampu menarik kereta lebih banyak.

Penemuan listrik oleh Michael Faraday membuat beberapa penemuan peralatan listrik yang diikuti penemuan motor listrik. Motor listrik kemudian digunakan untuk membuat trem listrik yang merupakan cikal bakal kereta api listrik. Kemudian Rudolf Diesel memunculkan kereta api bermesin diesel yang lebih bertenaga dan lebih efisien dibandingkan dengan lokomotif uap. Seiring dengan berkembangnya teknologi kelistrikan dan magnet yang lebih maju, dibuatlah kereta api magnet yang memiliki kecepatan di atas kecepatan kereta api biasa. Jepang dalam waktu dekade 1960-an mengoperasikan KA Super Ekspress Shinkanzen dengan rute Tokyo-Osaka yang akhirnya dikembangkan lagi sehingga menjangkau hampir seluruh Jepang. Kemudian Perancis mengoperasikan kereta api serupa dengan nama TGV.

MENGENAL KERETA API

Lokomotif

Lokomotif kereta api di Indonesia

Lokomotif adalah bagian dari rangkaian kereta api di mana terdapat mesin untuk menggerakkan kereta api. Biasanya lokomotif terletak paling depan dari rangkaian kereta api. Operator dari lokomotif disebut masinis. Masinis menjalankan kereta api berdasarkan perintah dari pusat pengendali perjalanan kereta api melalui sinyal yang terletak di pinggir jalur rel.

Berdasarkan mesinnya, lokomotif terbagi menjadi

1. Lokomotif uap. Merupakan cikal bakal mesin kereta api. Uap yang dihasilkan dari pemanasan air yang terletak di ketel uap digunakan untuk menggerakkan torak atau turbin dan selanjutkan disalurkan ke roda. Bahan bakarnya bisanya dari kayu bakar atau batu bara.
2. Lokomotif diesel mekanis. Menggunakan mesin diesel sebagai sumber tenaga yang kemudian ditransfer ke roda melalui transmisi mekanis. Lokomotif ini biasanya bertenaga kecil dan sangat jarang karena keterbatasan kemampuan dari transmisi mekanis untuk dapat mentransfer daya.
3. Lokomotif diesel elektrik. Merupakan lokomotif yang paling banyak populasinya. Mesin diesel dipakai untuk memutar generator agar mendapatkan energi listrik. Listrik tersebut dipakai untuk menggerakkan motor listrik besar yang langsung menggerakkan roda.
4. Lokomotif diesel hidrolik. Lokomotif ini menggunakan tenaga mesin diesel untuk memompa oli dan selanjutnya disalurkan ke perangkat hidrolik untuk menggerakkan roda. Lokomotif ini tidak sepopuler lokomotif diesel elektrik karena perawatan dan kemungkinan terjadi problem besar.
5. Lokomotif listrik. Lokomotif ini nomor dua paling populer setelah lokomotif diesel elektrik. Prinsip kerjanya hampir sama dengan lokomotif diesel elektrik, tapi tidak menghasilkan listrik sendiri. Listriknya diperoleh dari kabel transmisi di atas jalur kereta api. Jangkauan lokomotif ini terbatas hanya pada jalur yang tersedia jaringan transmisi listrik penyuplai tenaga.

Gerbong PENUMPANG

Kereta adalah kendaraan beroda yang merupakan bagian dari sebuah rangkaian kereta api dan digunakan untuk mengangkut penumpang. Kereta umumnya dilengkapi dengan sistem listrik, sistem hiburan audio visual, dan toilet. Di daerah atau negara-negara tertentu kereta dilengkapi dengan tempat tidur untuk perjalanan malam hari. Pada awalnya kereta hanya diberi tempat duduk dan tidak diberi atap (untuk kelas ekonomi) atau diberi atap (untuk kelas khusus). Di Eropa, khususnya Inggris, pada masa lampau setiap umumnya kereta dilengkapi kabin/kamar sendiri-sendiri untuk dua atau beberapa penumpang yang dilengkapi dengan pintu sendiri-sendiri. Di Amerika Serikat, kereta umumnya tertutup dan tidak dilengkapi dengan kabin/kamar tersendiri sebagaimana kereta yang umum dijumpai saat ini di Indonesia. Setiap kereta dilengkapi empat pintu dengan satu pintu di sisi kanan dan satu pintu di sisi kiri bodi kereta.

Kereta untuk tidur ditemukan di Amerika Serikat atas rancangan Pullman.

Rangkaian kereta. Lokomotif telah melepas diri dari rangkaian ini

Di Indonesia masyarakat lebih mengenal istilah gerbong penumpang, sedangkan kata kereta mengacu pada kereta api. Ini kurang tepat karena gerbong sebenarnya digunakan untuk mengangkut barang, bukan penumpang. Setiap kereta milik PT Kereta Api (Persero) memiliki nomor tersendiri. Format penomoran itu umumnya K[M|P][1|2|3]-xx(tahun pembuatan)x(jenis bogie)xx(nomor urut). Angka 1, 2, dan 3 menunjukkan kelas. K1 berarti Kereta 1 (kelas eksekutif), K2 berarti Kereta 2 (kelas bisnis), dan K3 berarti Kereta 3 (kelas ekonomi). Sementara KM berarti Kereta Makan, KMP berarti Kereta Makan dan Pembangkit, serta KP berarti Kereta dan Pembangkit

Gerbong

Gerbong adalah kendaraan beroda yang merupakan bagian dari sebuah rangkaian kereta api yang bukan merupakan lokomotif. Gerbong secara garis besar dibedakan atas dua jenis yaitu gerbong penumpang dan gerbong barang. Gerbong barang kemudian dibedakan lagi berdasarkan jenis muatannya antara lain:

• lori – gerbong terbuka, umumnya untuk mengangkut bahan galian tambang.
• tanki – gerbong untuk mengangkut muatan berbentuk cair.
• gerbong untuk mengangkut ternak.
• peti kemas.

Mengatur KA dengan signal

Mengatur Kereta Api dengan Sinyal

Itulah harapan yang dirintis setelah PT Lembaga Elektronika Nasional (LEN) mengembangkan Sistem Interlocking LEN (SIL-02). SIL-02 merupakan sistem sinyal elektrik pertama buatan dalam negeri yang akan mengatur lalu lintas kereta api. Jika sistem ini jadi diterapkan di seluruh jalur di Indonesia, sang operator di ruang kendali stasiun tidak perlu bersusah payah lagi. Tinggal memencet tombol pada panel kendali, sinyal elektrik akan segera mengatur lalu lintas kereta api.

Menurut Direktur PT LEN Dodi Hidayat Rivai, buah kerja LEN ini sebenarnya sudah dirintis sekitar tiga tahun lalu. Selain bekerja sama dengan PT Kereta Api Indonesia, LEN juga bekerja sama dengan Badan Pengkajian dan Penerapan Teknologi (BPPT). Pihak BPPT, kata Dodi, yang bertugas mengaudit kelaikan teknologi yang diterapkan LEN. Biaya yang dikeluarkan untuk mengembangkan satu sistem sinyal elektrik itu, kata dia, sekitar Rp 6 miliar. Secara umum, Dodi memaparkan, SIL-02 terdiri dari peralatan lapangan dan peralatan di ruang operator. Yang dimaksud dengan komponen lapangan adalah lampu sinyal, motor wesel untuk mengatur jalur rel, serta sirkuit rel untuk menentukan posisi kereta. Komponen itu akan aktif setelah sistem kunci (interlocking) dihidupkan. “Kalau salah satu kunci sudah bekerja, sistem tidak akan mengalihkannya ke kunci yang lain,” katanya. Artinya, jika ada kereta api yang masuk ke salah satu jalur, kereta yang lain tidak bisa masuk ke jalur yang sama. Sedangkan yang termasuk komponen di dalam ruang operator adalah prosesor untuk pengolahan sinyal yang berbasis PLC (programmable logic controller), sistem perkabelan, serta panel kendali tempat tombol-tombol, status sinyal, serta satu prosesor untuk mengendalikan sinyal. PLC ini berfungsi untuk mengatur dan mengendalikan sinyal masukan (input) dan keluaran (output).
Menurut Dodi Hidayat, secara keseluruhan, desain sistem sinyal mengacu pada sistem persinyalan yang sudah baku. Artinya, komponen yang ada di ruang operator dapat dihubungkan dengan segala macam peralatan lapangan. “Desain sistem sinyal ini multi-service, tidak tergantung pada salah satu merek sehingga dapat terkoneksi dengan peralatan lapangan merek apa saja,” ucapnya. Ia menambahkan, sistem SIL-02 ini juga dilengkapi peranti lunak untuk mengendalikan interlocking sinyal. Uniknya, peranti lunak ini berbeda untuk tiap stasiun. Perbedaan ini, kata dia, disesuaikan dengan jumlah rel yang ada di setiap stasiun. “Makin besar stasiun dan jumlah relnya, maka harga sistem makin mahal,” ujar Dodi. Menurut dia, peranti lunak yang dikembangkan mampu mendeteksi kesalahan. Sebab itulah, sistem sinyal elektrik yang dikembangkan memiliki dua prosesor. Fungsinya agar satu sama lain bisa saling mengecek kinerja sistem. “Prososer yang satu bisa mendeteksi jika ada kesalahan logika pada prososer yang lain,” katanya. Kesalahan itu, menurut Dodi, dapat segera diketahui operator di stasiun karena sistem akan memberi alarm peringatan atau print out data.

Ia berharap, produk dalam negeri ini mampu menggantikan ketergantungan Indonesia dari industri pemasok. “Jika ada kerusakan, perawatannya mudah dan bisa cepat ditangani,” katanya. Sejauh ini, ada tiga macam teknologi sistem persinyalan elektrik buatan luar negeri yang telah dipasang di Indonesia. Ketiganya, yakni Solid State Interlocking (SSI) buatan Prancis dan Inggris, Vital Processor Interlocking (VPI) buatan Amerika, serta Westinghouse Train Radio And Advance Control (Westrace) Interlocking buatan Australia, Amerika, Inggris, dan Spanyol. Karena diproduksi oleh pabrikan yang berbeda, peralatan interlocking mempunyai spesifikasi teknis yang berbeda pula. “Akibatnya,” kata Dodi, “jika ada kerusakan pada peralatan interlocking atau komponen elektronik lainnya, sistem hanya dapat diperbaiki atau diganti oleh pabrik pembuatnya.” Sejauh ini, sistem SSI telah dipasang pada jalur Jabotabek. Sedangkan sistem VPI digunakan pada jalur Bandung-Jakarta. Dan sistem Westrace Interlocking digunakan di jalur selatan, semisal Tasikmalaya, Banjar, dan Yogyakarta. Karenanya, LEN berharap, pihaknya diberi kesempatan untuk memugar sistem sinyal lebih dari 20 sistem. “Sebagai tahap awal, LEN mengusulkan agar sistem sinyal di jalur selatan diganti SIL-02,” katanya. yandhrie arvian

Cara Kerja Pemrosesan Sinyal SIL-02
Inilah sistem sinyal elektrik (SIL-02) pertama untuk mengatur lalu lintas kereta api buatan lokal. Pada dasarnya, peralatan SIL-02 dapat dipilah menjadi dua bagian. Peralatan di luar ruangan (vital outdoor equipment) dan peralatan di dalam ruangan. Peralatan di dalam ruangan dapat dibagi menjadi vital area dan non vital area.

Peralatan di luar ruangan

• Lampu sinyal: Memberi tanda kapan kereta api dapat masuk stasiun atau ke luar stasiun.
• Sirkuit rel: Mengidentifikasi dan memberi informasi pada kilometer berapa posisi kereta api sedang melaju menuju stasiun
• Motor Wesel: Mengatur persimpangan jalur rel kereta api
• Peralatan di dalam ruangan (wilayah vital): Dua modul PLC (programmable logic controller): Fungsi dua prosesor agar satu sama lain bisa saling mengecek kinerja sistem jika ada kesalahan logika
• Pemancar vital: Mengirimkan data vital
• Panel PLC: Menyampaikan informasi pada panel kendali di ruang operator dan terminal teknisi Peralatan di ruang operator (wilayah tidak vital)
• Terminal teknisi: Merekam seluruh kondisi perjalanan kereta api
• Panel kendali (local control panel): Tempat tombol-tombol, satu prosesor sederhana untuk mengendalikan sinyal, serta status sinyal ditampilkan

Cara Kerja:
Kereta api yang tengah melaju pada kilometer tertentu diidentifikasi posisinya oleh sirkuit rel (track circuit). Hasil identifikasi disampaikan ke PLC PLC akan menyampaikan pemrosesan data ke terminal teknisi dan panel kendali di ruang operator Operator akan membuat sebuah perintah. Perintah itu akan disampaikan ke Pusat Pelayanan Kereta Api (PPKA) dan ke panel PLC. Perintah itu untuk mengaktifkan apakah lampu sinyal akan hijau atau merah, serta akan mengatur persimpangan jalur rel kereta api (motor wesel)

PERSIGNALAN KERETA API

sistem persinyalan… sama… 2 aspek distant signal, dan 3 aspek home signal.

sistem signalling di indonesia sebenarnya nggak jauh beda (bahkan sama) dengan inggris. yaitu menggunakan sistem blok.

maksudnya, signal menentukan apakah blok di depan aman atau tidak.

jika 2 blok di depan aman, maka aspek hijau akan ditampilkan.
jika hanya 1 blok di depan aman, maka aspek kuning akan ditampilkan, dan kereta harus mengurangi kecepatan untuk menghadapi blok berikutnya yang kemungkinan beraspek merah.
jika blok di depan tidak aman (ada kereta lain di depan), maka aspek merah akan ditampilkan.

tambahan lain adalah deriver atau junction, biasanya berupa lima lampu \ | atau / yang menunjukkan kereta akan keluar di jalur yang mana setelah home signal dilewati.

<3> dipakai untuk menandakan kereta akan masuk bukan di sepur utama.

double white (dwarf), dipakai biasanya untuk langsir, artinya, kereta boleh bergerak sampai dwarf signal berikutnya dan memutar kembali.

dan satu lampu cadangan apabila salah satu dari signal itu tidak bisa berfungsi atau hanya mengeluarkan aspek merah.

lebih lanjut silahkan baca wikipedia dengan keyword “british signalling system”

• 5 bulan lalu

Pantograph KRL

Pantograph
> Kalau pantograph ini bisa dilipat, saya kira artinya bahwa KA
Amtrak
> tersebut bisa tetap operasional dengan menggunakan tenaga
diesel/lokomotif.

Setahu saya Acela ini tidak bisa beroperasi tanpa aliran listrik
(PLAA). Bombardier (produsen Acela) baru-baru ini meluncurkan
prototip Acela versi turbin gas.

Lihat: http://www.bombardier.com/en/1_0/pressrelease.jsp?
group=1_0&lan=en&action=view&mode=list&year=2002&id=1763&sCateg=1_0

Lok FL 9 dan penggantinya, Genesis, yang digunakan di Northeast
Corridor antara NYC dan Boston menggunakan sistem propulsi diesel
elektrik-elektrik. Artinya dia menggunakan mesin diesel biasa, namun
juga bisa mengambil arus listrik dari rel ketiga.

Di Inggris, lok elektrik-diesel elektrik kelas 73 sumber propulsi
utamanya adalah arus listrik dari rel ketiga, namun juga memiliki
mesin diesel 600 hp untuk cadangan (kalau melewati wesel yang
panjang) dan langsir di jalur cabang.

Pantograf lebih ideal untuk kecepatan sampai sekitar 300 km/jam.
Waktu eksperimen KA cepat di Perancis (pra-TGV), pantograf lok yang
dipakai sempat kepanasan dan leleh lho! Setelah itu disainnya
diperbaiki sehingga bisa dipakai untuk kecepatan tinggi.

Semua KA yang sekarang jalan di Indonesia, pakai rem angin sistem
Westinghouse (atau variannya Knorr) untuk pengereman seluruh rangkaian KA.
selain itu kalau untuk lok, ada independent brake (yg bekerja untuk lok
sendiri)
Untuk membuka rem (sehingga sepatu rem tidak menekan roda) maka kedalam
saluran angin sepanjang KA diisi tekanan, tekanan ini mengisi tabung
reservoir di tiap tiap gerbong melalui sebuah katup yang disebut “triple
valve”, katup ini akan mengisi reservoir selama tekanan udara ada di
saluran. begitu tekanan di saluran dikurangi, katup itu akan membuat udara
yang ada dalam reservoir menekan silinder rem. Semakin mendadak pengurangan
tekanan yg ada dalam saluran maka penekanan silinder rem akan makin kuat.

Sistem ini, kebalikan dari rem angin pada truk atau bis, kalau di truk
silinder ditekan dengan memberi kan tekanan angin langsung.

Kenapa begitu, ya supaya KA “fail safe”, misalnya rangkaian terputus,
otomatis selang antar rangkaiannya juga lepas, tekanan akan berkurang
mendadak dan rangkaian akan mengerem darurat. Kalau yang ditarik loko, ya
ngerem juga, rodanya terkunci, tapi kalau masinisnya tidak memperhatikan dan
main tarik terus, ya akibatnya roda rangkaian pada benjol nantinya.

Menurut gossip, KRL Holec yang kalau jalan bunyinya dukdukdukduk (apalagi
kalau pas lagi lewat Gambir dan kita ada dilantai bawahnya, kedengaran
jelas). Itu akibat pengisian salurannya kurang cepat, jadi roda sebagian
masih terkunci udah ditarik saja, jadi pada benjol, akibatnya ya bunyi
dukdukdukduk itu!

Nah menjawab pertanyaan sdr Ken:
Handel rem darurat itu fungsinya untuk membuka katup yang terhubung ke
saluran angin yg menjalar sepanjang KA. begitu ditarik, tekanan di saluran
akan terbuang, jadi KA akan mengerem darurat. nggak pakai sensor dll murah
meriah!

Di luar negeri, terutama AS, sekarang memang lagi dikembangkan sistem
pemberian komando pakai sinyal elektrik ke rangkaian, soalnya karena makin
panjangnya rangkaian, rambatan angin dalam saluran anginnya jadi relatif
lambat, jadi pengereman nggak bisa sekaligus, tapi mulai dari rangkaian yang
paling dekat loko. Penjalaran sinyal elektrik yang cepat, diharapkan dapat
mengatasi masalah itu.

Sistem Westinghouse ini aman sih aman, tapi kalau nggak hati hati, misalnya
waktu menggandeng rangkaian yang kosong semua reservoirnya, katup antar
gerbong lupa di buka, masinis melihat kalau saluran angin sudah terisi
dikiranya sudah OK dan berangkat, nanti waktu mau ngerem rangkaian pasti
terkejutnya setengah mati! Makanya sekarang kita sering melihat terutama
distasiun pemberangkatan awal, ada petugas yang bawa-bawa manometer, yang
akan pergi ke belakang rangkaian yang paling belakang dan melakukan
pengecekan apakah saluran anginnya terisi oleh pengisian yang dilakukan loko
di depan.

Ada lagi masalah kalau di Indonesia kita sering melihat adanya orang yang
naik KA disambungan antar KA, ini sangat membahayakan (bukan buat orangnya,
koit juga nggak apa itung itung mengurangi kebodohan di Indonesia, tapi buat
sistem pengereman KA). Kalau secara sengaja atau tidak katup saluran antar
gerbong tersenggol dan tertutup, maka waktu masinis melakukan pengereman,
sebagian rangkaian akan mengerem karena salurannya masih terhubung, tetapi
untuk gerbong yang salurannya tertutup dan sampai ke rangkaian paling
belakang rem tidak akan berfungsi, karena salurannya masih terisi tekanan
dan tertutup jadi tidak ikut turun tekanannya. (memang untuk membuka dan
menutup katup nggak semudah tersenggol, tapi dapat dibayangkan kalau diinjak
misalnya, tenaganya cukup untuk memutar katup!)
Sebaliknya kalau selangnya terinjak dan lepas, seluruh rangkaian akan
mengerem mendadak.

Sewaktu jaman SS, sistem pengereman yang digunakan adalah sistem vacuum
(makanya ornag kita bilang kalau rem mobil, motor atau sepedanya bagus,
disebut remnya pakem! dari vacuum). Kalau sistem ini sepanjang saluran rem
udara ditarik sampai vacuum untuk membuka rem. Waktu mau mengerem,
dibocorkan udara luar ke dalam saluran, maka akan menekan rem. Sama, kalau
rangkaian putus maka saluran akan langsung terisi udara, jadi mengerem
darurat. kekurangannya adalah tekan remnya tidak bisa sebesar sistem udara
tekan Westinghouse, soalnya tekanan udara normal kan cuma 1 atm, sedang
sistem Westinghouse bisa 6-7atm lebih malah.

Lok lok diesel lama BB301 ada sebaian yang mempunyai dua sistem,
Westinghouse dan vacuum, jadi di dalam lok ada kompressor dan pembangkit
vacuum.

Oh ya, pernah lihat kalau petugas waktu akan melangsir gerbong penumpang?
yang dilakukan pertama pasti menarik handel dibawah gerbong untuk
menghilangkan tekanan yang ada di dalam reservoir, supaya sepatu remnya
terangkat. Soalnya untuk menghemat waktu biasanya gerakan langsiran
dilakukan tanpa menghubungkan saluran angin rem! pengereman dilakukan
mengandalkan independent brake loko saja.

Di stasiun Pasarturi, saya pernah menyaksikan lok langsir D301 sedang
melangsir rangkaian gerbong penumpang. Waktu direm, roda lokonya memang
sudah berhenti, tapi masih keseret sama momentum rangkaian gerbong! lumayan
sampai beberapa meter sih ada.