The TEM18 looks a lot like the TEM2, and the two are often treated as practically the same locomotive. When it comes to brakes, that is only half true: the control pneumatics are shared, but the working part – brake cylinders and brake rigging – is built differently. Here are the key points for anyone maintaining both types or sourcing spare parts.
What they have in common
The pneumatic core is the same on both locomotives:
- driver's brake valve No. 394 (TEM18 uses the 394M version, some TEM18D units have No. 395);
- independent (locomotive) brake valve No. 254;
- air distributor No. 483;
- four main reservoirs of 250 l each;
- ZRD pressure governor – the compressor works between 7.5 and 8.5 kgf/cm².
As a result, brake valves, air distributors and their repair kits are in most cases suitable for both series.
The main difference: brake cylinders
TEM2: 4 brake cylinders, 254 mm (10″) in diameter, two per bogie. Each cylinder presses the brake shoes of several wheels on its side of the bogie through a system of levers, equalisers and rods.
TEM18: 12 brake cylinders No. 553, 8″ in diameter – one for every wheel. The cylinder sits next to the wheel and the rigging is short (the photo clearly shows the individual cylinders at the bogie wheels).
What this means in practice:
- fewer joints, pins and rods – less wear and play;
- more even shoe pressure on the wheels;
- piston stroke is adjusted separately for each wheel.
Different piston stroke limits
Because of the different design, the brake cylinder piston stroke limits also differ:
- TEM2: 75–100 mm when leaving the depot, no more than 125 mm in service;
- TEM18: 50–75 mm when leaving the depot, no more than 100 mm in service.
TEM2 limits must not be applied to the TEM18 – a common mistake in depots running both types.
Monitoring and protection
The TEM2 and its variants have no pressure switch that cuts traction when brake pipe pressure is low – the driver has to watch the gauges. The TEM18D has pressure switches: traction is blocked if brake pipe pressure drops below 4.0–4.5 kgf/cm², brake cylinder pressure is monitored, and an EPK No. 150 electro-pneumatic train-stop valve is fitted. Later units also have an air dryer and a link to the KLUB-U safety system.
Hand brake
- TEM2: acts on two axles of the front bogie.
- TEM18: acts on two axles of the rear bogie and holds the locomotive on gradients of up to 30 ‰.
What this means when ordering parts
- Valves No. 394 and No. 254, air distributor No. 483 and their components are mostly shared – just check the version.
- Brake cylinders, levers, rods and other rigging parts differ between the TEM2 and TEM18 – always state the locomotive series in your order.
- Not sure? Send us the part number or a photo and we will find the right part.
Brake equipment parts are available in our Vilnius warehouse.