Day 2: Drawer No. 2: Bogie Chassis
Bogie chassis (also known as gear towers) aren’t the most exciting of spare parts and are not really something that wear out, hence it’s unlikely you will ever need a spare one in order to keep your fleet running. That said, some locomotive chassis get stripped, thus offering up their gear towers for spares, others get acquired second-hand. They are useful for two reasons;
Occasionally I acquire a “bogieless” diesel chassis – a quick rummage in the spares box for a set of gear towers and bogies and you now have a working chassis
- Some diesels need their gear towers servicing and afterwards it is found that a new gear tower runs freer than the old one
- The top locating hole on the gear tower for the stub axle for the 25 tooth gear can split if the stub axle is a) pushed in from the wrong side, b) pushed in without aligning the knurled “teeth” to the grooves in the gear tower hole – I shall try to cover this in a later post next week.
So, from top left, moving left to right, we have;
Large diesel gear towers, mostly complete with gears. These are good for class 37/47/50/52/56/57 diesel locomotives. Ah … the virtues of common components!
The next compartment is split into two, with these components having elbowed their way into the bogie chassis box. They are (top) class 87/90 and class 158/159 bogie retaining clips – I had to put them somewhere! – and (bottom) class 20 chassis ends, which also retain the bogie chassis. The class 87/90 and class 158/159 bogie retaining clips are small plates with a lug which sit atop a grooved section in the split chassis, the lug points downwards and acts as a locating pin for the gear tower, stopping it from sliding out of the chassis. The class 20 chassis ends simply screw into the class 20 chassis at either end, encapsulating the gear towers.
Next we have two class 101 DMU chassis ends, which also act as bogie retainers, just like with the class 20. The screw into the chassis ends.
Top right we have small diesel gear towers to fit the class 20/25/33/HST/DMU/Railcar. These are actually becoming quite difficult to source although Bob Russell at BR Lines does stock them. The top stub axle hole for the 25 tooth pinion gear is known to split on these so proceed with caution if you are removing the stub axles. Personally, I do not remove the stub axles unless I really have to, preferring to give the gear towers and gears a good clean with a toothbrush and washing up liquid in warm (but not hot) water.
Middle row, far left, we have bogie retaining clips for the larger diesels classes 37/47/50/52/56/57 – again, isn’t it great that Poole Farish utilise common components! These don’t wear and shouldn’t need replacing. That said, many second-hand diesels come with these broken. It seems that people who are unsure of how to dismantle their diesel often tug at the bogie side frames, trying to pull them out. The resultant pressure on these clips snaps them off. These clips have to be unscrewed in order to remove the bogie chassis. In the picture you can see both black and white versions. The black ones are the original clips, which are no longer available. BR Lines had a replacement batch made which, in my experience, are an adequate substitute.
Moving along the middle row, we have some more large diesel gear towers, this time without any gears or stub axles in them. Also in this row we have class 87/90 gear towers, which consist of 3 x 16 tooth gears and 1 x 25 tooth gear. Far right (middle row) you can see a broken one – always worth keeping since you can salvage the gears from it!
On the bottom row we have some made up gear towers. Some of these are bagged. When working on multiple locos at any one time, it is easy to lose track of your work and which components belong to which loco. Additionally, faulty components, or those which need tweaking should not be tossed back into the spares box, but rather bagged and tagged so that you can easily identify them. I make a habit of bagging and tagging components that are either faulty, belong to a specific loco, or require further investigation. I also bag and tag chassis which are being worked on with essentials such as date worked on, job undertaken (service, re-gearing etc.), replaced compnents, pre/post current draw, current draw with bogies removed etc. This then later gets typed up on the master service log (spreadsheet) so that all work on all locomotives is recorded.
In essence, document where you are with your work if working on multiple locos so that you can stay organised.
Check back tomorrow for Drawer No. 3, Gearing & Bogies!