Ramblings from the Man Cave

I don't think I've encountered a topfeed on a pre-1942 P class boiler, but if 769 did have a topfeed, it would have been one with a small cover, but a cover that had a flatter bottom (compared to that fitted on untanked boilers, as per this Dean Goods):

 

Tank tops - not quite sure what a 645 pannier tank top would look like, but it was probably closer to a 1854 top than a 57xx top, the latter having a slightly more pronounced bump in the boiler.

 

Your bunker looks good.

 

 

Found this top view of 2772:

 

 

Clarification - pre-1942 top feeds probably didn't have covers. (But I'm still sceptical about one on a P class boiler.)

 

RCTS just says that 769 was one of not many to be so fitted, but without a date. It seems safe to assume that it was a (much) later addition. 

When was 769 withdrawn?

 

1 hour ago, Miss Prism said:

When was 769 withdrawn?

 

 

April 1930. The P class B4 boiler and pannier tanks in 1922 was the last boiler change, according to RCTS. 

Ok.

 

Having said I had not encountered a topfeed on a P class boiler, this one (which I assume is a P class boiler or a subclass) was staring me in the face all the while:

http://www.gwr.org.uk/pannier-pics/1693.jpg

 

I've been looking at the page with that picture on all this time too! Where are the top feed pipes routed - straight out of the cab front above the tanks? If so is 1673 (two images above) also so fitted? There is something immediately behind the tank fillers and there doesn't appear to be anything actually behind the engine, as is so often the case. If not then what is that pipe for? 

 

An unrelated question: what dictated the position of the tank vents? It seems to me to be arbitrary between two locations, front (as on 1693) or rear (as on 1693).

4 hours ago, richbrummitt said:

I've been looking at the page with that picture on all this time too! Where are the top feed pipes routed - straight out of the cab front above the tanks?

 

That's what I was looking for as well!!!! My feeling is that the feed pipes do not go along the top of the tank, a la classical later 57xx, but go straight down the sides of the boiler, like the arrangement in the Dean Goods pic above. The only other class I can think of having pre-1940 topfeeds is the 2021 class, and even so they were extremely rare. I will need to modify my 1693 picture caption.

 

I don't think 1673 is topfeed fitted. The thing behind the filler is the filler lid bouncer (or whatever it was officially called).

 

 

The pipe visible in the 1673 pic is I think the lubricator or blower pipe. Usually, these were hidden under the tanktops.

 

Tank vents seem to be fairly standard, about a foot or so to the rear of the filler, but 1673 is clearly non-standard.

 

Edited September 29, 2019 by Miss Prism

Not relevant to a model but would that require the tanks to be modified to have the space for the top feed? Though istr. tanks and boilers tended to remain together so once modified it would not be a recurring problem fitting tanks to a top feed boiler.

 

It's obvious now you tell me that the lid stop (something else for me to add) is what I was looking at. It was this detail on the picture of 1693 that made me wonder if there was a pipe exiting the cab on each side. This isn't visible elsewhere that I recall seeing and is not on the image of 2772 above.

 

There are other pictures of engines with vents in a rear position including 1815 and 1747 on the GWR.org.uk/nopanniers page.

Edited September 29, 2019 by richbrummitt

1 hour ago, richbrummitt said:

Not relevant to a model but would that require the tanks to be modified to have the space for the top feed?

 

I don't think so. There was usually plenty of room between the top of the tanks and the boiler, so piping (for lubricator and blower) could go into the space,

 

 

 

Quote

It was this detail on the picture of 1693 that made me wonder if there was a pipe exiting the cab on each side. This isn't visible elsewhere that I recall seeing and is not on the image of 2772 above.

 

The lubricator pipe cover at the cab end was I think always, or at least usually, on the right-hand side, as per this detail pic of 7714, because the lubricator and blower pipe cover was always on the rhs of the smokebox.

 

 

So I'm not sure what that thing/cab hole is on the left-hand side of 1693. It is just possible it is one of the boiler feed pipes (with the other on the right-hand side), but why go into the cab when their destination is the injectors below the tank?

 

Quote

There are other pictures of engines with vents in a rear position including 1815 and 1747 on the GWR.org.uk/nopanniers page.

 

There are always exceptions. The difficult thing to judge is whether they are class exceptions or just unusual exceptions within the class.