Engine tender coupling query

[Lost property]

Watching "Train Truckers " last night, as an aside, as with the heavy haulage / aviation programmes, the content is always interesting, but, the commentary and inane graphics showing what could go wrong is, frankly, dire, and I was curious about the pin securing the tender to the engine. From the way it was being "assisted " into position, I assume it's an interference fit ?

Hence my query, purely out of interest, is, how often would this pin have been removed when in service and what inspection methods would have been used to decide if it was still serviceable ?

 

[BigB]

The pins pass through the coupling and the tender so if not 100% aligned there will be some persuasion required, but remember there are also mini "buffers" between the two to keep tension. You need to push the tender onto the engine (or vice versa) to insert the pin and usually this takes a bit of a thump to go all the way through. Once in place and the forces removed it will then be subject to some rotational forces. Inspection is based on wear and ovality against tolerances for that engine type.

 

[Lost property]

The pins pass through the coupling and the tender so if not 100% aligned there will be some persuasion required, but remember there are also mini "buffers" between the two to keep tension. You need to push the tender onto the engine (or vice versa) to insert the pin and usually this takes a bit of a thump to go all the way through. Once in place and the forces removed it will then be subject to some rotational forces. Inspection is based on wear and ovality against tolerances for that engine type.

Thanks for that explanation. I was curious as to how the pin would be inspected and even more so without the NDT techniques currently available given, as you say, ovality and tolerances would be the inspection method used

 

[Ken H]

Thanks for that explanation. I was curious as to how the pin would be inspected and even more so without the NDT techniques currently available given, as you say, ovality and tolerances would be the inspection method used

Probably replace it at regular intervals. Replacing components on condition is a relatively new concept.

 

[BigB]

Probably replace it at regular intervals. Replacing components on condition is a relatively new concept.

That depends on how you define "new" - many pre-nationalisation locos have tolerances to be measured as part of overhauls, they are not straightforward replacements. Without unique identifying marks such as in aviation it is hard to accurately time expire parts resulting in wholesale replacements at overhauls.

I've seen many examples of items retired due to wear but kept on a shelf as they may be "useful"... metal skip please... though people do sometimes want to buy cleaned up worn buckeye locking pins as mementos, which is always good for us...

 

[2192]

Didn't a few Britannia tender couplings fail when the class first came out?

 

[341o2]

There are a couple of incidents detailed in this thread, but the major problem was that the wheels slipped on the axles

 

[tynesider]

Something I've always been curious about, is how is the area accessed for the pin to be inserted / removed?

I've seen a few solo tenders with the drawbar exposed (theres one outside the NRM at the moment). Once the drawbar is pushed into the locomotive, then surely it will be directly below the floor of the footplate? Do these need to be removed in order to access the pin? Similarly, I understand some locomotives have smaller, contingency drawbars, to the side of the main one. Are these also accessed the same way?