Poll: GWR Pannier Tanks; time for a modern spec OO loco.

[Miss Prism]

On 10/02/2022 at 18:27, Neal Ball said:

So what you are saying is that a 8750 loco started life with no top feed; had it added at some point after 1942 and then later had it removed. I wonder what the thinking behind that was.

 

Before 1942, the backfeed P class boiler was universal*. There were hundreds of them. After 1942, new P class boilers were top feed, and the older boilers were upgraded. With normal subsequent boiler swapping, the number of topfeed boilers therefore began to proliferate, and the number of backfeed boilers declined. The upgrading of the older backfeed type was probably quite rapid, but I couldn't put a timescale on it.

 

* True in respect of 57xx/8750, but I should have noted that there were a number of topfeed P class boilers in existence long before 1942, which were used on Dean Goods.

 

Edited October 13, 2022 by Miss Prism
caveat added on Dean Goods locos

[Neal Ball]

2 minutes ago, Miss Prism said:

 

Before 1942, the backfeed P class boiler was universal. There were hundreds of them. After 1942, new P class boilers were top feed, and the older boilers were upgraded. With normal subsequent boiler swapping, the number of topfeed boilers therefore began to proliferate, and the number of backfeed boilers declined. The upgrading of the older backfeed type was probably quite rapid, but I couldn't put a timescale on it.

 

fascinating thanks Miss Prism and Mike

[PMP]

2 hours ago, Neal Ball said:

 

Thanks very much Mike,

 

So what you are saying is that a 8750 loco started life with no top feed; had it added at some point after 1942 and then later had it removed. I wonder what the thinking behind that was.

 

Re: 54xx 

When I started the research into the Panniers I decided almost straight away to lump all the post 1928 Collett Panniers  together - rightly our wrongly!

 

In addition to @The Stationmasterand @Miss Prismnotes re the swapping of boilers with and without top feeds also happened within the 57xx low cab family too. 
Re the 64/74xx they too started with no top feed. The same thing occurred with the 54xx and I believe, but not found an example yet, that a small number of them had reversion to non top feed, after top feed fitting.

 

The reason why the 54xx is a good choice for a different locomotive is the wheel size, giving it a distinct visual difference.  It’s not the simple diameter that’s different, the key point that people miss is the number of spokes, 14 on the smaller engines and 16 on the 54’s.
The body sits slightly higher too, as the buffers are positioned differently, making a simple body swap unviable for a manufacturer, assuming they want it to look accurate.

Edited February 10, 2022 by PMP
Add pic

[Captain Kernow]

1 hour ago, Neal Ball said:

So what you are saying is that a 8750 loco started life with no top feed; had it added at some point after 1942 and then later had it removed. I wonder what the thinking behind that was.

Another example (albeit not pannier) is 1458. In the late 1950s there are photos of it with a top feed, but by the time it was working on the Kington and Presteign goods in the early 1960s, it had no top feed.

 

[melmerby]

Topfeeds appeared fairly early on, at least pre WW1 on certain engines, where they were incorporated with the safety valve bonnet.

The County tanks started to get them from 1912, the last batch of 10 being built with them, some Saints also had them pre WW1.

Plenty of other examples.

Top feeds on domed boilers e.g. Pannier Tanks are not so common until later years.

 

The "Frenchies" had them from new in 1902/3 in front of the domes.

 

[Neal Ball]

6 hours ago, melmerby said:

….Top feeds on Pannier Tanks are not so common until later years.

 

They appeared from 1942.

 

Hence why as a modeller from the 1930’s I have consistently campaigned for Pannier tank locos with no top feeds.

 

Thanks for your comments Keith.

[2ManySpams]

12 hours ago, Neal Ball said:

 

Thanks very much Mike,

 

So what you are saying is that a 8750 loco started life with no top feed; had it added at some point after 1942 and then later had it removed. I wonder what the thinking behind that was.

 

 

 

Hi Neal, just to clarify what Mike and Miss P are saying here...

 

When a loco went into shops for an overhaul, generally the item that took longest to do was refurbing the boiler. As such you could have a loco sitting around, sans boiler, waiting for that work to be done prior to returning to traffic.

 

To cut down the amount of time a loco spent in the shops not earning money, it became common practice to swap boilers. So on entry to the works the loco would have it's boiler removed and a ready refurbed one put back in its place. The original boiler would be refurbed and would get put into a different loco. 

 

Thus if a loco went into works with a boiler that had a top feed, it would emerge with a different boiler which may or may not have had a top feed. It wasn't the top feed that was taken on or off the loco but the entire boiler.

[Neal Ball]

10 minutes ago, 2ManySpams said:

 

Hi Neal, just to clarify what Mike and Miss P are saying here...

 

When a loco went into shops for an overhaul, generally the item that took longest to do was refurbing the boiler. As such you could have a loco sitting around, sans boiler, waiting for that work to be done prior to returning to traffic.

 

To cut down the amount of time a loco spent in the shops not earning money, it became common practice to swap boilers. So on entry to the works the loco would have it's boiler removed and a ready refurbed one put back in its place. The original boiler would be refurbed and would get put into a different loco. 

 

Thus if a loco went into works with a boiler that had a top feed, it would emerge with a different boiler which may or may not have had a top feed. It wasn't the top feed that was taken on or off the loco but the entire boiler.

Yes thanks, I’ve always known that.

 

But I’m surprised that if a new top feed arrangement was introduced from 1942 that there wasn’t a section of the works assigned to putting the new arrangements onto the next boilers, ready for the next frame to arrive.

 

In my mind I’m comparing it to a car production line….. BMW have revised how a part for a car is done, therefore everything after that would get the upgraded idea.

 

I realise the two production lines are very different, but I’m just surprised when taking a loco into the works, that the old ideas continued….  
 

Turning that back to our models, it’s a wonder that a Pannier with no top feed hasn’t been done already then!

[Siberian Snooper]

Boilers aren't cheap and only life expired boilers would be replaced with a new top feed variety. To remove the backhead feed from a firebox would need the old backhead removed a new one made and putting a hole in the boiler barrel for the new top feed. Replacing the backhead requires the removal of some very expensive stays which tend to end up as scrap and the lap rivets, reasonably cheap.

 

Stays, locate and hold the inner firebox in position and are made from either high tensile steel or Monel Metal.

 

 

 

 

Edited February 11, 2022 by Siberian Snooper
to add the what stays are.

[BMacdermott]

14 hours ago, The Stationmaster said:

Incidentally although they were a numerically small class and originally very limited in geographical distribution it would have been nice to see 54XX in the list.

 

Hello Neal and Mike

 

In The 00 Wishlist Poll 2019 (the last 'main' Poll to run), the 54xx/74xx was the highest-voted pannier tank (apart from the 15xx which has now been made).

 

Brian (on behalf of The 00 Poll Team)

[melmerby]

3 hours ago, Neal Ball said:

They appeared from 1942.

 

Hence why as a modeller from the 1930’s I have consistently campaigned for Pannier tank locos with no top feeds.

 

Thanks for your comments Keith.

Some domed boilers got top feeds long before 1942, that's why I was not specifically picking out panniers which your edit of my quote did.

[Compound2632]

9 hours ago, melmerby said:

The "Frenchies" had them from new in 1902/3 in front of the domes.

 

As built by the Société Alsacienne but those were of course not Great Western boilers. I'm sure Churchward was well aware of top feed from his reading of the literature or from discussions at the professional associations but these would have been the first examples of which he had day to day practical experience. How much did the de Glehn design of top feed influence what Churchward subsequently had designed?

[Miss Prism]

Jim Champ uploaded Churchward's seminal 1906 IMechE paper - 'Large Locomotive Boilers' to the gwr-elist recently. Bottom-feed, side-feed, back-feed and top-feed are all featured there, and although the Frenchmen are not mentioned specifically, it shows how Churchward developed his thinking from the practices of many other countries and companies.

 

 

Edited February 11, 2022 by Miss Prism
a couple of words now in the correct order!

[2ManySpams]

3 hours ago, Neal Ball said:

Yes thanks, I’ve always known that.

 

 

Apologies Neal, I wasn't trying to teach granny to suck eggs. I misinterpreted your reply as not twigging that the reason top feeds appeared and disappeared was due to the boiler swaps. No offence intended. My reply might be useful to others that didn't already know though. 

[Neal Ball]

1 hour ago, 2ManySpams said:

 

Apologies Neal, I wasn't trying to teach granny to suck eggs. I misinterpreted your reply as not twigging that the reason top feeds appeared and disappeared was due to the boiler swaps. No offence intended. My reply might be useful to others that didn't already know though. 

 

No offence taken thank you.

[The Stationmaster]

20 hours ago, Neal Ball said:

 

Thanks very much Mike,

 

So what you are saying is that a 8750 loco started life with no top feed; had it added at some point after 1942 and then later had it removed. I wonder what the thinking behind that was.

 

Re: 54xx 

When I started the research into the Panniers I decided almost straight away to lump all the post 1928 Collett Panniers  together - rightly our wrongly!

 

I spent ages going through all of the modern Panniers, taking down details off the wheel sizes, wheelbase etc. Trawling through Pannier Papers and a couple of my other books to get a measure of the detail differences. 

 

It was time well spent as I then moved onto the Pre-WW1 locos and the majority of that research came from the site gwr.org.uk 

 

I compared what I was trying to achieve on the Toplight poll, which 5 years down the line looks a bit of a mess and I don't think is as concise as it could have been. Hence why all the Collett ones are together. The only exception was the 64xx with the question being for a no topfeed loco as I thought there might have been a call for the loco in as built condition. Clearly the answer to that was no.

 

Thanks again for your comments.

 

 

No Neal - outshopped (i.e on building) with a top feed boiler but later seen without a top feed as boiler changes took place.  

 

So the manufacturer needs to include both a top feed and a back head feed option in their range if doing the 57XX and the 8750 (for those reboilered at some stage without trop feed .  So something to add to the basic lists of variations within the class which in summary are 57XX with or without automatic brake, and with or without snaphead rivetted tanks and 8750 with or without automatic brakes. Plus seasonal steam heat pipes on the automatic brake fitted engines.  

 

And that's before you even think about the 97XX sub group which I suspect might be that bit too specialised but then equally we have seen in recent years how models of small specialised groups of engines and stock do seem to sell rather well (not that anyone has published the numbers of how many they've made/sold).

[PMP]

12 minutes ago, The Stationmaster said:

 So something to add to the basic lists of variations within the class which in summary are 57XX with or without automatic brake, and with or without snaphead rivetted tanks and 8750 with or without automatic brakes. Plus seasonal steam heat pipes on the automatic brake fitted engines.  

 

P.s. and the variation in tank filler types, as some high cabs had screw top fillers rather than clamp type…

[Neal Ball]

1 hour ago, The Stationmaster said:

No Neal - outshopped (i.e on building) with a top feed boiler but later seen without a top feed as boiler changes took place.  

 

So the manufacturer needs to include both a top feed and a back head feed option in their range if doing the 57XX and the 8750 (for those reboilered at some stage without trop feed .  So something to add to the basic lists of variations within the class which in summary are 57XX with or without automatic brake, and with or without snaphead rivetted tanks and 8750 with or without automatic brakes. Plus seasonal steam heat pipes on the automatic brake fitted engines.  

 

And that's before you even think about the 97XX sub group which I suspect might be that bit too specialised but then equally we have seen in recent years how models of small specialised groups of engines and stock do seem to sell rather well (not that anyone has published the numbers of how many they've made/sold).

Thanks for that Mike. Clearly a minefield of variation… fir a company that was proud of its standardisation!

[melmerby]

4 hours ago, Neal Ball said:

Thanks for that Mike. Clearly a minefield of variation… fir a company that was proud of its standardisation!

Hmmm.

They did standardise on boilers, wheel size, cylinders etc. but each of those standard components could have many variations but still fit any class they were meant for.

Some standard size boilers may have had backfeed, side feed & top feed at various times during their use.

[Neal Ball]

42 minutes ago, melmerby said:

Hmmm.

They did standardise on boilers, wheel size, cylinders etc. but each of those standard components could have many variations but still fit any class they were meant for.

Some standard size boilers may have had backfeed, side feed & top feed at various times during their use.

Different times….

 

It was a standard, but not what we would call standard today. 
 

interesting though that Standard for a particular loco or carriage was only defined by one aspect.
 

In our case here, wheel size and maybe wheelbase, when the boiler and everything about it could be yesterdays standard… 

 

Interesting to say the least

[Craigw]

7 hours ago, Neal Ball said:

 

In our case here, wheel size and maybe wheelbase, when the boiler and everything about it could be yesterdays standard… 

 

Interesting to say the least

 

A standard or design change would be used for new work. If fitting top feed to boilers was not cost effective then it would not have been done, they would simply have used the boilers until they are life expired.

 

Even now a new feature would not be retrofitted unless there is a safety imperative.

 

Standards (then and now) make sense when you understand manufacturing and Engineering.

 

Craig W

[The Stationmaster]

14 hours ago, melmerby said:

Hmmm.

They did standardise on boilers, wheel size, cylinders etc. but each of those standard components could have many variations but still fit any class they were meant for.

Some standard size boilers may have had backfeed, side feed & top feed at various times during their use.

Plus numerous minor parts and things like nuts and bolts which meant that GW loco depot stores carried much smaller (i.e. less varied) stock levels than was the case elsewhere, in particular on the LNER where injectors alone involved numerous differences between constituent companies and group designs.  

 

As far as Swindon top feed design was concerned Holcroft relates some of the early experiments carried out by drawing office staff using buckets of water to test different arrangements of the trays that were to be sited inside the boiler below the top feed.

[The Johnster]

6 hours ago, The Stationmaster said:

 

As far as Swindon top feed design was concerned Holcroft relates some of the early experiments carried out by drawing office staff using buckets of water to test different arrangements of the trays that were to be sited inside the boiler below the top feed.

 

The comedy potential of this is considerable...

[6892 Oakhill Grange]

On 11/02/2022 at 19:11, The Stationmaster said:

No Neal - outshopped (i.e on building) with a top feed boiler but later seen without a top feed as boiler changes took place.  

 

So the manufacturer needs to include both a top feed and a back head feed option in their range if doing the 57XX and the 8750 (for those reboilered at some stage without trop feed .  So something to add to the basic lists of variations within the class which in summary are 57XX with or without automatic brake, and with or without snaphead rivetted tanks and 8750 with or without automatic brakes. Plus seasonal steam heat pipes on the automatic brake fitted engines.  

 

And that's before you even think about the 97XX sub group which I suspect might be that bit too specialised but then equally we have seen in recent years how models of small specialised groups of engines and stock do seem to sell rather well (not that anyone has published the numbers of how many they've made/sold).

I haven’t read pages 2 through 8, so apologies if necessary.

 

Not to mention 2 different types of cab door for the 57xx and with / without shutter variations (correct me if I am wrong) for the 8750..  Then you need to tool up 2 types of brake gear for the chassis.

[6892 Oakhill Grange]

On 11/02/2022 at 19:11, The Stationmaster said:

No Neal - outshopped (i.e on building) with a top feed boiler but later seen without a top feed as boiler changes took place.  

 

So the manufacturer needs to include both a top feed and a back head feed option in their range if doing the 57XX and the 8750 (for those reboilered at some stage without trop feed .  So something to add to the basic lists of variations within the class which in summary are 57XX with or without automatic brake, and with or without snaphead rivetted tanks and 8750 with or without automatic brakes. Plus seasonal steam heat pipes on the automatic brake fitted engines.  

 

And that's before you even think about the 97XX sub group which I suspect might be that bit too specialised but then equally we have seen in recent years how models of small specialised groups of engines and stock do seem to sell rather well (not that anyone has published the numbers of how many they've made/sold).

A question formed in my mind.  Did the tanks last the full 25+ year life of the riveted engines? If replacement tanks were required were they welded?  Did the number of riveted tanks decline over time?  Is there an example of a loco carrying one riveted and one welded?

 

Oakhill