The 10A Allocation

According to the RAIB report, the original design of gudgeon pin and those manufactured on restoration were both 3" diameter by 8 tpi. I think the reference to the coarse thread is because of the decision to use a castellated nut which was highly likely to mean that the (rather massive) preload on the gudgeon pin nut could not be accurately applied, as the final position was dictated by the castellations (one suspects that even with a 10 or 12 tpi thread, the same issue could have occurred). The SR design used a plain nut. The report mentions that castellated nuts were used on BR and LMS locos but the design of the little end was different and with a smaller diameter thread on the pin. The report suggests that the restorers may not have had access to original drawings (at least of this component) when rebuilding the loco (I take that to mean they did not have the drawings) which was presumably a learning point. (the work was not done at Carnforth)

 

And no doubt there are many (perhaps even more) women who know men like that...

Noel

 

2-1/2" dia x 6TPI on Standard locos.

 

Thanks, so even coarser surprisingly. There must have been some other feature to ensure that the taper was fully drawn into the bore in the crosshead. I guess you could machine the nut (or washer if there is one) until it fits exactly.

 

And probably not a few men who know women like that! I know of a few but am thankfully not associated with them!

But back to Tangmere...

Richard.

 

Your last sentence sums the situation up.

 

Indeed. Damned autocorrect.

 

An update on Galatea would be appreciated. Glad Leander was out yesterday. Thanks

 

If you look at Tangmere’s overall record it was pretty good

 

A feature not confined to steam traction. As a typical example the preserved Class 14 fleet is increasingly becoming less standard as owners make modifications to their locomotives to meet their operating needs but - as not all operating conditions are identical - the solutions have tended to move away from any "standard" designs; add in the (usual) lack of drawings or technical documentation and the possibilities of (expensive) damage becomes a greater possibility.

In terms of steam locomotives I am reminded of the recent problems of metal specifications where IIRC the certified metal quality disagreed with the actual quality leading to locomotive failures - proving that maintenance repair and overhaul of steam traction is a responsibility not to be taken lightly.

 

Did someone in the supply chain make a mistake, or was there skulduggery? (Fraudulent materials/marking has become quite a problem in the aircraft world.)

Noel

 

Is this about the copper that was used for stays, but was later found to have no arsenic in it?

 

I remember from earlier discussions on Nat Pres - The quality of some metals being imported is suspect, because the material is being falsely certified, ie. falsified documentation is being produced and sent out from the Far East with steel shipments. If I remember correctly, material has been bought legitimately, but has been found to be of a specification other than that which it should be according to the paperwork.

Just found the link -
https://www.national-preservation.c...tion-falsified-in-japan.1022062/#post-1952203

Richard.