Bulleid Pacifics - Past or Present

There is also official BR photographic evidence of 36001 running at Oxted without the oscillating gear, with the cylinder end-caps in full view. See Robertson, p.91. As a matter of fact, this photo appears on the Wikipedia article I helped to edit (plug, plug, but any improvements/comments will be welcomed). Another trawl through my sources states that the oscillating gear enabled the sleeves to have fore, aft and limited axial rotation, which not only attempted to reduce wear, but also to equalise temperature within the cylinder. There were two separate systems for moving the sleeve valves. The fore and aft movement was controlled by an extension of the valve spindles, and is visually similar to Gresley 'conjugated' valve gear and GW four-cylinder examples (Robertson, 48 ). I imagine the axial arrangement was similar to that used on the 2039 'Hartland Point' trials, ie. via a rotating shaft driven by a Morse chain from the leading coupled axle on both bogies.

 

[Typed this before I saw Bullleid Pacific's post above] Yep, as I suspected. The lugs which protruded forwards for the oscillating gear were prone to fracture and the gear was disconnected in the later trials to improve reliability.

If you imagine a sleeve inside a cylinder (like a liner), and a piston within that sleeve, and both the sleeve and piston are reciprocating back and forth, plus you're also rotating the sleeve a few degrees each stoke, the complexity of lubrication and sealing are a bit mind boggling!

So yes it gave a very compact design, allowing you to get 3 cylinders into the bogie, but at a price. Maybe it could be done with modern materials and design techniques though?

Source is is "Leader - Steam's Last Chance" by Kevin Robertson. Highly recommended.

 

Bulleid Pacific

I have just noticed you kind remark about my illustration of 34053 Sir Keith Park. It is always good to hear the work involved in getting all the intricate detail into the illustrations is noticed and appreciated!

The share issue to get Sir Keith back in steam for next year is going well, but the more people who subscribed the better. See http://www.southern-locomotives.co.uk/Company/Shareholders_Scheme.html

The illustration will be made available to the general public later next year.

 

My copy of the print is now framed and gracing the dining room wall.

http://nick301.photos.us.com/p62269390.html

 

Seems we're both right regarding the oscillating gear if this quote is accurate :
"On page 81 of Kevin Robertson's "The Leader Project Fiasco or Triumph?"
appears the statement that following a failure of the sleeve valve on the
No1 bogie 'the bold step was made to remove the oscillating gear completely
from the No1 bogie' the paragraph goes on to say that the oscillating gear
was left intact on the No2 bogie."

 

Indeed. He also mention's that the No.1 end had been run up in the workshop and then revesred whilst still in motion, damaging a number of components, and it may never have been quite the same again after that. Not that there weren't other issues that would have scuppered it anyway like the weight, and probabaly the dry-lined firebox.

 

Yes the reversing incident made a few unplanned modifications to the gear.
I wonder if the weight problem could have been cured by making it oil fired and having the fireman's controls in the cab along with the driver. This would have enabled the boiler to be mounted centrally on the frames and the concrete ballast dispensed with. Does the book mention the reasoning behind the dry lined forebox?

 

Have a look at a sleeve valve aero engine if you want to be boggled! Here's an animation of a Bristol Hercules.

http://www.youtube.com/watch?v=_vrvep_YOio

Cheers
Alan

 

I think that Bulleid's intention all along was that the locomotives would be oil fired but the politics of the day prevented it. Certainly the intention with the Turf Burner.

 

Nice one. Thanks for the link.

 

No problem! I did however notice that my village of residence was spelled incorrectly in the mailing address, which has alerted me to what SLL's records say (as I've undertaken the installment option, this shouldn't affect me until the share certificate is sent out upon completion of the £250 cost next year, in which case I'll send them a reminder). It was probably down to my poor print-handwriting on the original share application form. Regardless, it arrived safely, and keep up the good work!

 

SLL are a very good organisation when it comes to overhauling and maintaining bulleid locos. They have realistic views. 34028 and 34070 are both getting good use.

However one loco that barely seems to have had much use is 34046. What is happening with it? The boiler ticket seems to be being wasted. It is being fitted out for mainline and awaiting its new tender?

 

I think you find that SLL just do the overhauling and not the maintanence....

 

Well, I suppose it is the Swanage crews who use the locomotives on a day-to-day basis, and as such the Swanage Motive Power Department is best placed to undertake the maintenance side of things, even if the work involved may annoy some people...

 

What work would annoy some people?

 

Sorry Lewisb06, i knew it was some arrangement like that, having read about it before. Just didnt word it right.

 

No worries at all 850

 

Apologies from me as well for reading too much into your reply to LN850, but it came across as though you were a bit miffed about the fact that the railway maintains the locomotives between overhauls, rather than SLL.

 

No...was just clarifying the situation.....
No worries at all....appologies accepted...

Its the joys of reading the written english language.

Happens time and time again on here...
Post written and then mis-interpreted....

SLL restore and then SR maintain them to working order.

 

The English Language as a means of communication, loses most of its power; when used on Internet Forums.