Trains Can't Stop Suddenly, Here Are Two Reasons

JAKARTA - The collision incident between a train and a truck in Semarang and Bandar Lampung last Tuesday received mixed responses from the public.

One of the concerns is how the braking system on rail transportation is.

KAI's VP of Public Relations Joni Martinus said trains are a type of transportation that cannot brake suddenly.

This means that trains need a braking distance to really stop.

"Unlike land transportation in general, trains have characteristics that technically cannot be braking suddenly. For this reason, we urge the public to be more vigilant and careful before crossing a level," he told reporters, Friday, July 21.

Joni said there were two factors that caused the train not to be able to brake suddenly.

First, long and heavy train series. The longer and heavier the series, the distance it takes for trains to really stop will be even longer.

In Indonesia, continued Joni, an average of one series of passenger trains consist of 8 to 12 trains (carriages) weighing up to 600 tons, not including passengers and their luggage.

"With these conditions, a lot of energy will be needed to stop the train series," he explained.

Second, said Joni, the braking system. Trains in Indonesia generally use an air brake system. The way it works is to compress the air and store it until the braking process occurs.

When the driver activates the braking system, the air will be distributed through small pipes along the wheels and make friction on the wheels. This friction will make the train stop.

Even though the train is equipped with an emergency brake, this brake still can't stop suddenly. This brake only produces more energy and greater air pressure to stop the train faster," he said.

So, continued Joni, even though the driver has seen someone break through the railroadstop, then carry out the braking process, it will still require a braking distance to really stop.

"This will cause a collision if the braking distance is not met," he explained.

The factors that affect the braking distance are:

1. Train speed. The higher the speed of the train, the longer the braking distance.

2. The slope of the rail road (flat, decreasing, or incline).

3. Percentage of braking which is indicated by the magnitude of the brake style.

4. Types of train (passenger train / goods).

5. Type of brake (composite block/iron block).

6. Weather conditions.

7. And various other technical factors.

Joni said the brakes on the train array work with air pressure. The brake performance system on wheels is connected to the piston and cylinder arrays.

The mechanism that reduces air pressure on trains will force brakes to lock with wheels.

If the pressure is released suddenly, continued Joni, it will cause a braking that is not uniform, so the brakes work first from the point of exit of the air.

"Businessers that are not uniform can cause trains or carriages to slip, be dragged, and even roll over," he explained.

Therefore, Joni said KAI reminded again that the procedure for crossing a level crossing is to stop at the 'STOP' sign, look left-right, if you are sure it is safe, then you can pass. Crossing doors, sirens, and crossing guards are just security aids.

The main safety tool is on the traffic signs "STOP". So if the community at the crossing has seen a train even though it is still far away, then it should stop first until the train passes," concluded Joni.

As for Law No. 22 of 2009 concerning Road Transport Traffic, article 114 states that at a level crossing between the railway and road lanes, drivers are required:

a. Stop when the signal sounds, the railroad doorstop has begun to be closed and/or there are other signs.

b. Prioritizing trains, and

c. Give the main rights to vehicles that first cross the rails.