Self-weighing tenders

[Pyewipe Junction]

I recently saw a photo of a B1 with a self-weighing tender.

Can anyone tell me what the purpose of these was?

I assume they were not very successful or useful, or we would have seen more of them. Or perhaps they came too late in the day to be justified on the grounds of cost.

Were they fitted to any other classes (ex-LNER or otherwise)?

[lielestosbrat]

From what I have read about them the self weighing tenders where used in conjunction with Dynamometer cars. They where used to gain a more accurate reading of how much coal was used on a run and when and where.

Rob

[badwolf]

The LMS seemed to have more of these than anyone, I am not sure but they don`t have a GWR equivalent, the loco men didn`t like them because it was not possible to stack extra coal, the LMS ones lasted nearly till the end of steam .

[Saint Johnstoun]

The purpose of these was to measure coal consumption. The coal bunker was a separate unit suspended on pivots which were connected to a steelyard at the rear of the unit. The whole assembly could be 'fixed' when the loco was working and released when it was necessary to weigh the contents.

They could be used in conjunction with dynamometer car tests but often testing was carried out without.

They fell into disuse for their intended purpose and the bunkers were fixed, steelyards removed, and continued as normal tenders until scrapped, usually with the loco.

At least 2 B1s ran with these, and 2 K1s, the LMS had four which ran with various black fives.

I have drawings of both types and have built models for Black five and B1!