Bulleid Pacifics - Past or Present

And 35029? It can't need that much more work than 10 & 11, surely?

 

Very long term project I believe

 

Ellerman Lines?

There’s surely no justification to do more than make the wheels and motion spin around in situ at the NRM again is there?

Are you getting confused with 35027?

Simon

 

I think a humorous posting to emphasise the magnitude of work required to re-steam 35010 and 35011

 

I follow the Riley's FB page quite closely and it's been a couple of years since there was anything on 35009. Last updates were frames being taken to the (old) works and a picture of refurbished bogie wheels and both of those were probably three years ago. May be getting done on the quiet of course, but it looks like they're not short of things to occupy themselves with.

 

As said earlier I think it’s basically the project that keeps Riley’s staff occupied/skilled when contract work and work on the 5s is scarce.

 

Have You read the Bulletin 10 from BTC and can give us a link?
I would love to read it myself.

Maybe Syphons were put in because Chapelon had done it in his 4-8-0 prewar welded steel fireboxes.
Syphons take volume away from firebox and lessens time for combustion due to higher velocity.
In tubes flames die instantly and the extra heat absorbed from syphons reduce both pipe evaporation and superheat.
Is there a written source for Bulleids claiming firebox safety?

 

Britania was 42 sq grate,
max evaporation 31410lbs/h
boiler efficiency 66%

MN unrebuilt 48.5 sq grate,
max steam 34000
efficiency 61%


Max IHP when burning 3000lbs/h
Britania 1620 72% boiler efficiency
MN 1300 70% boiler efficiency

I asked sometimes ago if it was considered to omit syphons in the six new fireboxes?

 

I don't see how that can be considered a viable option - it is fundamentally changing the design of the locomotive to something new. I don't know how the certification of steam locos for use on private heritage railways works and my understanding on how it works for Network Rail is also limited, but from what I have gleamed from comments on this forum, I would be willing to bet that if you were to take the siphons out of a Bulleid firebox it would be considered changing the design enough that whatever grandfather rights are available for Bulleids to operate on the mainline would not be applicable

 

I believe ( but aren’t certain) that a Bulleid boiler was built without siphons for comparison purposes in BR days so drawings might well exist. Removal of the siphons would also require a new throat plate and probably outer wrapper due to staying requirements.

 

And the inner firebox without any thermic siphons was both tested at Rugby and the results published as a printed report but it remained in the boiler afterwards with the locomotive in general traffic.

It is fair to say that despite the higher superheat temperature when out on the road it was not reckoned a strong engine but there can have been no risk of a siphon failing with the fire door open.

 

A firebox arrangement drawing for a Merchant Navy without thermic syphons exists. It is dated 1950.

 

35022 visited Rugby Testing Station on three occasions, 19-3-52 to 02-10-52, 10-3-53 to 07-5-53 and 05-12-53 to 25-01-54. The short notes state it was in for multiple jet/single jet blastpipe testing, but the first visit is a long one.

 

Comparative tests with and without syphons of the 141 R 807 were carried out at the Vitry test plant in 1953.
The removal of the syphons led to the following consequences.
-the vaporization rate increased by 2 to 3% and the boiler efficiency by 3 to 5%.
- water consumption decreased by 5% and that of oil (as for oil firing) by 6 to 10%.
- the superheating temperature increased by 25 °C and the temperature of the gases at the outlet of the tubes decreased by 20 °C.
It should be noted that the draught increased when the syphons were removed, as they are an obstacle to the movement of
gas in the hearth.
The vaporization rate increased because the speed of the gases in the tubes increased and there was therefore a better heat exchange.
In order to confirm the results obtained, the tests were resumed with the 141 R 919 in 1954. The results obtained with the
141 R 807 were then confirmed!!
These results obtained during the removal of the syphons on the two 141 Rs have undoubtedly called into question certain designs, because
in 1955, tests to remove the syphon were carried out on the 141 P 189. In this case, the removal of the syphon appeared as
very clearly unfavourable!
The result obtained with the 141 P is therefore in total contradiction with that of the two 141 R.
Following these tests, it was decided to remove the syphons on ALL the 141 Rs when they were undergoing major overhaul.
On the other hand, they were maintained on the 141 P!!

R 807: test file 30.A 3413 and 3416.
R 919: test file 30.A 3417.

Not all 141Rs lost their syphons.

 

Thank You for a very interesting update on syphons knowledge.
Are the test files You mention accessible somewhere?
I read french well enough concerning steam locomotives.

 

They should be available from somewhere within SNCF. Their archives are in Le Mans, I believe.

 

As did I, These figures were taken from the interchange trials ? and were by their own admission unreliable because acheiving a stable firing/ output rate was nigh on impossible.
On the other hand the recent Watercress line ? video about Can Pac with Doctor munchkin from the NRM claims the maximum firing rate and therefore steaming rate for a Merchant Navy has 'never been reached'
even with two fireman , no mention of how much of it was being shot out the blastpipe ? or how the injectors could cope with this skies the limit output...

 

Here s a question, are todays restored Spam Cans better/ more reliable than they were in BR service ?

 

New to me that boiler efficiency was measured and evaluated during interchange trials?
Sounds more like a Rugby job.
My source was Cox.