The NS train signal system

Technically there is a 'new' and an 'old' lighting system. The only difference between the two is in SR 401c. The old system has the 'reversed L' front sign while the new system has the 'A' front sign. Reason for the change to the 'A' front sign was the fact that Germany made the 'A' sign obligatory in on their tracks and a most services from the Netherlands to Germany are done by NS trains. Only trains made before 1960 are capable of showing the old 'reversed L' front signal these days.

Front signals

One white light

(SR 401a, SR 403d)

This is the front- or backside of a shunting powervehicle.

Two white lights

(SR 401b)

The white lights have to be at an equal height.
This is the front side of a pushed train, being not a passenger train. This is only used by vehicles which can not show three white lights.

Three white lights

(SR 401c)

Two lights on equal heigth with a third above, in 'A' form or 'reversed L'.
This is the front of a train.
Pushed trains with a maximum speed of 30 km/h do not have to use a front sign during the daylight.
Pushed worktrains may use a blinking red light at night on track that is out of service.

Rear signals

Two red lights, may or may not blink

(SR 403a/b)

This is shown by the last vehicle of a train or shunting power vehicle

One red blinking light

(SR 403c)

This is shown by the last vehicle of a train, not fit for passenger transportation. During the daytime, a non burning lantarn may be used

Signals on special vehicles

Vehicles not made to have front or rear signs can use red flags to make the sign.

One red flag

(SR 412)
The flag must be on or next to the vehicle. It has to be shown at special vehicles, even if the train or shunting part is moved. The TRR specifies what a special car is.
At night the flag is not visible. Lamps have to be used. The color of the lamps depends on the track on which the vehicle is.
RED <--[F Vehicle B]--> RED
Used on free track on single, wrong and double track which has signals for both directions.
WHITE <--[F Vehicle B]--> RED
Used on free track with normal use of in one direction signalled track. The signals in the other direction are in position stop, so a train from that side is not to be exected.
WHITE <--[F Vehicle B]--> WHITE
Used on track which is out of service. All signals leading to this track are in position stop, so no trafic to this track is possible.