BR Standard class 6 No. 72010 'Hengist' and Clan Discussion Thread

I'm sure there is workplace politics at play as well - after all, it would be remarkable if (in the case of BR) you had an organisation with probably close to a dozen major workshops and four competing design offices that didn't have major arguments on policy about new designs. I think there is a tendency from an enthusiast point of view to imagine that you are starting from a clean sheet of paper and set out the ideal designs: life is much messier than that. It would hardly be beyond the bounds of possibility were some design element to be accepted as a compromise to keep one or other of the regions "on side".

Tom

 

And there we were trying to understand the logic in Ireland of taking an average of the gauges in use there, and ending up with 5' - 3"!

 

Coming back to the original question on patterns (!) the drawings for or engine state that "Pattern to suit SL/DE/20095 finished size of which is shown by etched lines". 20095 is the class 5 drawing.

Other news is that our pattern maker, Tony, is back up to speed again and is about to start the valve cylinder core box. Whereas the main cylinder core is essentially straightforward, the valve cylinder internal shape is a lot more complex. We are finalising the changes connected with the move to direct oil lubrication as recommended in the CLIP report

https://www.theclanproject.org/design/Clan_Design_Clip.php

See section 5. The lubrication hole will be moved outwards slightly to ensure that the oil is injected at the mid point of the piston. In order to ensure that the pattern can be used for class 7 locos with atomised injection, the internal gallery will be retained. An internal boss will be added, similar to the liner bolt location boss, so that oil is fed direct to a hole in the liner.

 

Thanks Ian, great to hear that these best practice features are being incorporated. I’m sure we will reap the benefits when it comes to operating the loco.

 

Help Needed!


Yesterday we took a delivery from Forrest Engineering in Glasgow. These castings had been ordered a long, long time ago and Forrest were having a clear out and sent them to us. We think the casting marked 19 or 61 is the body for the graduable steam brake valve along with the handle and bottom lid (73). Other parts may be from the valve. The casting top left is foxing me unless its the top half of the valve and would be the other way up. Our problem is that we don't have the drawing. Can anyone confirm my thinking?

 

it is the top of the steam brake mechanism

 

Thanks

 

I have just seen the latest posting on the News page.
https://www.theclanproject.org/Clan_News.php

To those of us who are not more intricately involved in this build, this is an impressive view of the work involved in creating new drawings and designs for a new/modified locomotive. All work which goes on behind the scenes and of which we are vastly grateful.
Well done Will and all our draughters, thank you!!!
It is also great to see some of Forrest Engineering's contributions coming to the fore, they made quite a few items in earlier years. Don't know how actively we have used them recently.
Very helpful and obliging I understand.
Progress continues .......!

 

Latest news is that John, Geoff and I visited Tyseley a couple of weeks a couple of weeks ago to view the modification on 71000 to the rear cylinder cover. This now feature an extension to support the front of the slidebars. Movement of the slidebars is well documented in Bill Harvey's book "60 Years in Steam". Loosening of the slidebar fasteners was a factor in the 1960 Settle rail accident. This modification is proposed in the Clan Improvement Report (https://www.theclanproject.org/design/Clan_Design_Clip.php) and we were keen to see this in reality. Our thanks go to the 71000 team for hosting the visit.

We noted that the Cylinder Relief Valve needed to move from the 3 o'clock or 9 o'clock position (depending on which side it was located) to the 6 o'clock position. Interestingly the front cylinder cover has the valve at the 6 o'clock position. Does anyone know the reasoning behind the difference in original locations? 71000 retains the original screw in valve whereas the lot 242 class 6 design details the slightly longer flanged version.

Will has been modelling the lot 242 cylinder/slidebar bracket/slidebar design in 3D as an "originally designed" condition. We can now build on this to incorporate the slidebar support on the cylinder cover to ensure that everything is in the right position.

Last week, CTL Seal moved our frames to provide more room on the right hand side of the frames so that we can get the Asquith drill into position. Mike H made a start yesterday by drilling/reaming the holes for 2 of the 3 brake hanger brackets. We need to do a bit of work on the fit of the dragbox in the frames before we can start drilling/reaming the bolt holes.

 

Would point out that this feature also exists on the Caprotti Standard 5, but i dont believe that there are surviving drawings.

https://www.flickr.com/photos/taffytank/15147108379

https://www.ephotozine.com/photo/british-caprotti-valve-gear-6086651

 

The position of the hind cylinder relief valves on the Standard 5s 73000-73154 was at 30 degrees to the vertical. 73155 to 73171 were fitted with modified hind cylinder covers with the relief valves at 3 or 9 o'clock. The relief valves fitted to the later cylinder covers were of the bolt on type. The front cylinder covers were also modified to accept the bolt on relief valves. Many of the earlier Standard 5s in the series 73000 to 73124 received the modified cylinder covers. The hind relief valves on the Caprotti locos 73124 to 73154 could not be moved to the new position because of the casting that was in the way, so the covers were modified to accept the bolt on relief valves in the original position, as your photo shows.

 

Deleted

 

We now have a copy of the Caprotti class 5 hind cylinder cover SL/DE/22220