Friday 11th - Maintenance

 Report by Graham

The team was at Winchcombe this week for Type-A exterior exams on the carriages taken out of the covid rakes which would normally be in service, and which hopefully next year might see service again! We had been running 8 coach rakes, but the covid trains only have 6.

All the usual under side and body side checks. With the vehicles having been unused for a long period we were also on the look-out for anything that needs attention just because of that, eg. oiling of drying brake linkages.

A rotten step board was found…

New ones are nicely painted all over on the outside, but when fitted a dirty great hole gets drilled through them for the bolt. Hopefully paint or preservative is put down the bolt hole before they are fitted, but when we find them in this state it is difficult to tell.

 

We do find that the step board bolts can sometimes be tightened up to the point that a dimple is created in the top of the board. This can collect water when it rains and might also be a contributory factor. 

We have three types of braking arrangements on our BR1 and Commonwealth bogies.  The early BR1s have non compensated brakes, the later ones have compensated. The Commonwealth bogie brakes are compensated and a few of ours have automatic slack adjusters.  The older vehicles were from the start only vacuum braked but some of the newer (a relative term), were both vacuum and air braked, known as dual braked.  All of our vehicles are now only vacuum braked.

The difference between non compensated and compensated is that the latter have two levers included in the brake rigging on each bogie to balance the brake force between the axles.  This evens out brake block wear and the extra linkages make adjustment much easier.  The automatic slack adjuster does what it says on the tin.  From a routine maintenance point of view the thing that we need to keep an eye on, in addition to brake block wear is the gate gap or control distance.  With the vacuum destroyed, this should be 5/8ths of an inch.  This is the distance between the end of the adjuster furthest from the brake blocks and the adjustment bracket. 

Vehicles with slack adjusters can initially look like there is too much slack at the brake blocks compared to other vehicles that are manually adjusted and this is just another one of the things to take into account.

We also found a vehicle with oily axle boxes. At the back of the axle box is a cork seal…

…which can just be seen when viewed from underneath, and it is supposed to help keep the oil inside the axle box. Some seepage is ok, but it eventually needs attention. This one was noted on the exam sheet for monitoring and future attention.

Whilst we were in the yard we noticed one of the old unrestored carriages still had a box full of batteries…

…although it’s dynamo didn’t look it would help charge them…

So, another set of checks done, and a few more items on the jobs list to go back and do in a future visit.