BR Mk.1 Carriages - those built with external window frames

[Western Star]

I wish to know in which year Mk.1 corridor coaches were first built with the external window frames; ideally which Lot was the first to be subject to the modification.  This question does not apply to Mk.1 corridor stock that was built without external window frames and gained that modification at a subsequent repair / overhaul.

 

thank you, Graham Beare

Edited October 19, 2022 by Western Star

[ISW]

22 hours ago, Western Star said:

I wish to know in which year Mk.1 corridor coaches were first built with the external window frames; ideally which Lot was the first to be subject to the modification

Graham,

 

In regards to the installation of aluminium window frames, according to "British Railway Mark 1 Coaches" by Keith Parkin (Page 86) it says "Most stock built from lot 30573 (1960) onwards had these from new ... ".

 

Hope that helps.

 

Ian 

[Western Star]

Ian,

 

Thank you, your reply is just what I wanted to know.

 

regards, Graham

[Hal Nail]

16 hours ago, ISW said:

Graham,

 

In regards to the installation of aluminium window frames, according to "British Railway Mark 1 Coaches" by Keith Parkin (Page 86) it says "Most stock built from lot 30573 (1960) onwards had these from new ... ".

 

Hope that helps.

 

Ian 

Presume in terms of total numbers that's quite well into the build programme so a smallish proportion?

 

Numerous discussions on here about this but inconclusive how quickly the replacement frames became widespread. At one point earlier this summer the midhants had two original formal SOs in the same rake which apparently had never been modified.

[ISW]

39 minutes ago, Hal Nail said:

Presume in terms of total numbers that's quite well into the build programme so a smallish proportion?

Just based on the 'list' of Lot numbers, 30573 occurs 70-75% of the way through the list so 25-30% seem to have be built with the aluminium window frames. Obviously, not all Lot number have the same number of vehicles, but this should provide a rough idea.

 

Ian

[45655]

4 hours ago, Hal Nail said:

At one point earlier this summer the midhants had two original formal SOs in the same rake which apparently had never been modified.

MHR has three Mark 1 TSOs which retain the original type windows with the glass clamped onto the rear of the body side panels and sealed with mastic.  4549 and 4600 were in use from day 1 in 1977, having been delivered by rail in 1976 over the original track, before it was lifted.  They have now been in use by MHR for twice as long as they were by BR.  The third, 3906, was a later acquisition, an Eastleigh-built example of an early type TSO in virtually original condition - so they stripped out the toilets at the last overhaul and converted them into a buggy storage area!

 

It's worth noting that there were two distinct types of external window frame fitted to Mark 1s.  The first retained the use of mastic seals and many (probably most) early vehicles were retrofitted with these.  I don't know if any were built new with this type, though.  The second used rubber glands to retain the glass and from the 1960 date I suspect that it is these to which Parkin refers.  This type was generally fitted with double glazed main lights in first class areas although these have proved a maintenance liability in preservation so many have been replaced with plain glass.

 

Keith

Alton.

[ISW]

12 minutes ago, 45655 said:

 The second used rubber glands to retain the glass and from the 1960 date I suspect that it is these to which Parkin refers.

Keith and @Western Star,

 

Just for clarity, here's what the Keith Parkin book actually says (I suppose I should have done this first, instead of typing an extract):

 

So, yes, he was referring to the aluminium frames.

 

Ian

[45125]

Alloy window frames first appeared with the Bardic style of window frame, the glass of this was clamped in in similar fashion to the original windows. Then came the two styles of frames that used a rubber sealing strip. These frames were supplied by two firms Beclawat and Widney which are not identical.