Brake test
A brake test (abbreviation: Brpr ) on the railroad refers to a process that is part of the preparatory service before train journeys, during which the functionality of the braking system of the vehicles in the train set is checked. The application and release of the brakes to be tested is checked at a standstill.
In certain situations, both rail and road vehicles, it is intended to check whether the application and release of the brakes is working properly while driving. This is also called a brake test in some places and, in addition to checking the brakes, is used to get a feel for the road and rail conditions, especially in autumn and winter.
Railway in Germany
General
Rail vehicles are usually braked with compressed air brakes. In order to check the function of the entire braking system, a brake test is carried out after the train has been assembled. The brake test is regulated in Germany in the brake regulation ("BreVo", VDV -chrift 757). This VDV publication largely corresponds to the wording of Directive 915.01 (operating and checking brakes during operation) issued by Deutsche Bahn AG .
The procedure and the forms of the brake test are precisely prescribed and are only carried out by trained brake test authorized persons (formerly brake officers). There are special brake test signals that can be transmitted with light signals, hand signals or verbally for communication between those authorized to brake tests and the train driver. The brake test is an elementary requirement for train preparation.
Full brake test
Due date
The full brake test must be carried out in the following cases:
- On a newly assembled train
- If a train was coupled to more than two coupling points of the wagon train by placing / releasing pre-tested or untested vehicles / vehicle groups.
- The simplified brake test can be used for up to two coupling points
- Once a day on unchanged trains, usually before the first train journey.
- If a train was parked for more than 24 hours
- In the event of irregularities
- Before certain slopes
- If in the so-called announcement of the free travel path of up to 40 km / h instead of the otherwise usual 25 km / h top ranks must be
Process (with separate status path)
The driver (or the person authorized to use the brake test) secures the train using parking brakes and fills the main air line to 5 bar. The state transition is now started.
The person authorized to carry out the brake test now checks:
- the release status of the brakes on the first vehicle behind the occupied locomotive
- Determine the released condition and condition of the brakes on all vehicles (on both sides of the wagon train - there and back)
- Brakes that are switched off and not tagged must be switched on
- the correct setting of the brake position change
- the correct setting of the load change
- as well as proper coupling.
In response to the “ apply brake ” signal ( Zp 6) from the person authorized to test the brake, the railway vehicle driver (or the person authorized to operate the brake test using a stationary brake test system ) begins the leak test. If the pressure drop within one minute is no more than 0.3 bar for passenger trains or 0.5 bar for freight trains, the line is deemed to be tight and the actual brake test can begin. Possibly. the driver (who is authorized to use the brake test) switches to the filling and releasing position and thus fills the main air line to 5 bar again in order to return to the initial state. The brake is then applied by lowering the pressure in the HL to 4.2 bar. The person authorized to test the brakes walks along the train and checks whether the brakes have been applied to each axle (in the case of bogie cars, to each bogie). On trains that run with magnetic rail brakes (braking position R + Mg), an emergency braking is carried out and the function of all magnetic rail brakes is also checked.
Then he gives the driver the signal " release the brake " (Zp 7). The brakes are released and the person authorized to test brake checks again whether the brakes have released. Furthermore, after releasing the last vehicle, a continuity test is carried out on the main air line and the automatic application and release of the brakes is checked. After the inspection has been completed, the person authorized to test the brakes gives the signal " Brake OK " (Zp 8), the railroad vehicle driver has to confirm the recording of the signal (through Zp 1 or verbally). The person authorized to perform the brake test, who carries out the full brake test, acknowledges this if necessary with a brake test notification slip.
Simplified brake test
The simplified brake test is carried out to ensure that all brakes can be properly applied and released by the driver's brake valve, which is operated while driving, and that the main air line is connected throughout.
Due date
The brake test notification slip enables the person authorized to carry out the brake test to recognize whether a full brake test has already been carried out. The simplified brake test must be carried out in the following cases:
- if the prescribed full brake test was not carried out with the driver's brake valve to be operated during the train journey
- if a train has been added and / or temporarily separated, with a maximum of two coupling points
- if a train was parked for between one and 24 hours
- If a train with a locomotive was parked unchanged for up to 1 hour, the driver's cab brake test may be used
- if the main air line was interrupted in the meantime due to irregularities (e.g. due to a changed air hose or an emergency brake pulled)
- if wagons were switched to braking position R + Mg
- if vehicles have to be connected to the main air line when maneuvering
- before certain gradients
procedure
As with a full brake test, the train must be secured against unintentional movements by means of parking brakes. The person authorized to test the brake test first checks on the i. d. Usually last vehicle, whether the brake is released. In the case of freight trains, a “continuity test” is then carried out on the main air line on the last vehicle by opening the air shut-off valve for 15 seconds. The automatic application and release of the brakes is checked. Alternatively, if there is a radio link, the air shut-off valve can be closed as soon as the driver reports a drop in pressure. This is the case if the pressure in the main air line drops by more than 0.5 bar. This step is not necessary for passenger trains. Then he gives the driver the order “apply the brake”. The driver now initiates service braking by lowering the main air line pressure to 4.2 bar. The person authorized to test the brakes will now check that the brakes have been properly applied.
Then he gives the order to release the brakes. If this also happens properly, the driver is informed that the brake is OK.
Depending on the situation, the brake test is carried out by the driver, the train driver , the wagon master , the shunting attendant or the train preparer .
Cab brake test
Due date
The driver's cab brake test is a function test of the brake control devices of the leading vehicle as well as the locked state of devices of the brake system that are inactive at this point in time. It is to be applied
- when changing the driver's cab as part of the operational turnaround,
- if an unchanged train was parked for up to an hour with the driver's brake valve shut off,
- if, in the case of multiple traction, a leading vehicle (usually a locomotive) is removed and the second traction vehicle then becomes the leading vehicle
- if the control device for the brake has been changed on radio-controlled locomotives
- before the first train journey after the end of a journey with an air brake head .
procedure
- In the driver's cab last used, the train is secured with emergency braking and additional parking brakes and the associated driver's brake valve is shut off
- Release the brakes in the newly occupied driver's cab
- Then apply the brakes again with service braking (pressure reduction in the main air line to approx. 4.2 bar) and lock the driver's brake valve and unlock it again after 10 seconds
- By temporarily shutting off the driver's brake valve, it is to be ensured that no other driver's brake valve in the train unit unintentionally supplies air
- Release the brakes again with the help of the aligner
Railway in Switzerland
The Swiss Federal Railways are working on automating the brake test on freight trains in order to enable one-man operation for the delivery and collection of individual wagons. Wagons that have received automatic couplings as part of an operational test have been equipped with a system that enables a brake test to be carried out automatically. The driver can carry out the entire process from the driver's cab using a tablet. Sensors attached to the car measure the pressure in the brake cylinder and brake linkage, communication between the car and the end device takes place via mobile radio. The system has been tested since summer 2017, and SBB Cargo is aiming for full approval by mid-2020.
See also
Web links
Individual evidence
- ↑ DB AG (Ed.): Guideline 915.01 Operating and testing brakes during operation . Module 915.0103 page 1 .
- ↑ DB AG (Ed.): Guideline 915.01 Operating and testing brakes during operation . Module 915.0103A01 page 1 + 2 .
- ↑ DB AG (Ed.): Guideline 915.01 Operating and testing brakes during operation . Module 915.0104 page 1 .
- ↑ Automatic brake test . In: Eisenbahn-Revue International . No. 7 , July 2019, ISSN 1421-2811 , p. 355 .