Maunsell Restriction Coaches

That's interesting. The railway press always used to refer to the kinetic envelope, seems the mistake was earlier in my education then.

https://www.britannica.com/science/kinetics

I get the impression from the linked entry, that different branches of science use kinetics, kinematics and dynamics for subtly different meanings. I am a 'bear of little brain' but it seems that the difference is down to whether one considers the forces applied or just the actual motions?

Kinematic (no s) has always meant to me an old fashioned word for 'to do with the cinema'.

 

I agree that gauging is complex. The more one delves into the subject, the more seem to be the complications. A further factor is that loading gauges do change over time and have been doing so since railways began.
The LBSC fitted many of its brake coaches with very wide guards’ side look-outs. When these were applied to the longer bogie coaches, the greater overhang appears to have created problems in certain locations, leading to some of the guards’ look-outs being reduced in overall width (from 9ft 2in to 8ft 9in).
https://www.bluebell-railway.co.uk/bluebell/pics/coach949.html

Maunsell built a number of rakes of “Restriction 1” corridor stock for services to the Kent Coast on the SECR section and to Eastbourne via the curved Lewes tunnel on the LBSC section. These were 8ft 6in over body sides, presumably about 8ft 9in over door handles & hinges and 9ft over foot-boards. Interestingly, the Maunsell N15/ King Arthur class engines were within gauge to haul these services in spite of having fairly large outside cylinders.
In later years, the wider “Restriction 4” stock became acceptable on nearly all routes, but the Class 207 “East Sussex” DEMUs were built to “Restriction 1” widths as late as 1962.

I have never seen any diagrams that illustrate the height and width limits of the SR carriage “Restriction Codes”, which leaves open the question of exactly how they related to published loading gauge diagrams (such as those on @Jimc web-site). I think that “Restriction 1” may have been closely aligned to the SECR loading gauge.

 

As you say its complex. I know most about the GWR. They had a standard loading gauge, but beyond that the General Appendix to the rule book listed all sorts of exceptions. So for example:
73' * 9'6 stock was not permitted off the GWR nor on most lines that had never been broad gauge.
73' * 9'0 stock was allowed to Salisbury SR, but nowhere else on the Southern.
63'6 * 9'3 stock was not allowed on SR at all
60' * 9' stock was allowed on LSW section and most LBSC, but not SEC.
and there were a whole set of max measurements for Tonbridge and Crowhurst, Hastings and Winchelsea and a list of other lines, which included no longer than 50'.
So that implies you're correct that restriction 1 closely matched SEC.

 

I do not think there was ever any particular problem with Lewes Tunnel. The Newhaven boat trains used to be made up of Bulleid and Mark 1 Restriction 4 stock. As a child in the early 60's we travelled annually on the Eastbourne - Glasgow car sleeper with Mark 1 Sleeping cars in the consist. I'm pretty sure that the entire former LBSCR system could handle Restriction 4 stock. Indeed were not the 1930s 6PUL and 6PAN electric units Restriction 4 stock?

Peter

 

Please see this web-page:

https://www.bluebell-railway.co.uk/bluebell/cw/restriction.html

Lewes Tunnel was barred to Restriction 4 carriages in March 1927 after problems had been experienced with the then new Maunsell stock. An exception was made for the Newhaven Boat Train of R4 stock, which was allowed to pass provided that no other train was in the tunnel at the same time. Info from David Gould - "Maunsell's SR Steam Carriage Stock".

The prohibition on R4 stock was lifted in 1935. It seems likely that the tracks in the tunnel were realigned as part of the 1935 Eastbourne electrification scheme.

 

Well I never knew that. It is suprising what you learn on NP. Every day a school day.

Thanks

Peter

 

I have a query for Southern carriage experts.

Apart from the Lynton & Barnstaple, the SR route with the most severe clearance restrictions was the Canterbury & Whitstable. Tyler Hill tunnel had only 12 ft headroom, with vehicles limited to a maximum height of 11ft 6in.

The attached photo is said to show a train at Whitstable Harbour in 1927 (Passenger trains were withdrawn from the line in 1931). We see a Stirling R-class 0-6-0T with cut-down chimney, hauling 2 bogie coaches.

But what is the origin of those coaches? Looking through the David Gould book "Bogie Carriages of the SE&CR", I can find no mention of any bogie carriages being built or modified for use on the "Crab & Winkle" line. The carriages in the photo have arc roofs and are unlike standard Wainwright vehicles with their elliptical roofs.

Possibly they are of LC&DR origin? Thanks in advance to anyone who can shed any light.

 

While I cannot answer your question my Grandfather, who started on the railway at Canterbury West, told me that when those coaches were cut down no allowance was made for the ventilators on the roofs. They were knocked of on the first trip through the tunnel.

Sent from my SM-A105FN using Tapatalk

 

Oh well. Seems no-one is able to either confirm that these were ex-LCDR carriages or offer an alternative identification.

A diagram in Gould's book indicates that LCDR bogie carriages were 11ft 7½in to roof top but the roof ventilators protruded a few more inches. So your grandfather's anecdote seems plausible. Certainly, the carriages in the Whitstable Harbour photo had roof ventilators removed.

Another photo shows a train emerging from Tyler Hill tunnel. Although of poor quality, it can be seen that the carriage roof edges were very close to the tunnel.

 

I could ask on the SECR Society e-group if you like?

Tom

 

Yes please, so long as it's not any trouble.

Thanks in advance for any info that you can uncover.

 

I got the following replies, in sequence, which I think covers it:

"They are LCDR four-wheel coaches. Only the 1st edition of Gould had the 4- & 6-wheel coaches; in the later edition restricted itself to bogie coaches. A Photograph from the 1920s shows no. 126 with a rake of four coaches. See Canterbury & Whitstable railway by Brian Hart p 136. These replaced elderly SER four wheelers just before the grouping."

"According to R W Kidner’s “Southern Railway branch line trains” (1984), when “new” stock was required for the Canterbury & Whitstable in 1922, 6 four-compt seconds of 1901/2 were converted to all-third and 5 to first/third compos, while there were five third brakes of 1887-9. All had ventilators and duckets removed and smaller wheels fitted. Close-coupled in pairs, three pairs of thirds and five pairs of third brake and compo. All 4-wheelers (although most if not all of the brake carriages had been built as 6-wheelers). SR numbers quoted as thirds 1770-5, third brake 3659-63 and compos 5790-4. The first photo certainly looks like two bogie carriages, but I wonder if it might actually be two close-coupled pairs?"

"I think it's two close coupled pairs...one can't see the slight gap behind the first coach because the door is in the way, but the ends of the first and second pair can be seen and also the slight gap in the middle of the rear pair.
Also the foot boards are not full length and one can see the gap in them within the pairs. Look identical in another photo I have of a train on the C&W."
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Tom

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Thanks greatly for the explanations. Today has certainly been a learning day for me!