Double class 37 trials on the Paddington to Cardiff route 1960s.

[Merle Haggard]

The re-geared 37s with CP7 bogies (80mph) have their two diverts come in at fairly low speeds - 20 and 35mph.

Original 90mph (106mph gearing) 37s have their divert speeds set at 26 and 49mph, and upper speed performance seems much better by comparison looking at performance logs.

Though, as I understand it while the refurbished 37s with an alternator can be immediately opened to full power, unrefurbished ones could be easily overloaded at low speeds, so initial acceleration is probably better on refurbished examples?

47s can be opened to full power straightaway with the only potential issue being rail conditions, the locos themselves can take it.

mods note - split from this thread

Thanks.
Totally tangential - but I remember seeing at Paddington ca. 1968 the pairs of 37s on (??? South Wales) Inter City trains timed at 100 - very short lived and a bit mysterious (but said to be re-geared) - any idea of the background?

 

[hexagon789]

Thanks.
Totally tangential - but I remember seeing at Paddington ca. 1968 the pairs of 37s on (??? South Wales) Inter City trains timed at 100 - very short lived and a bit mysterious (but said to be re-geared) - any idea of the background?

No re-gearing, that's a myth.

As built all of 37s, 50s and 55s shared the same bogie design and gearing (106mph continuous on mid-life tyres).

The background was presumably a desire to accelerate the best business trains, two sections of 100mph were authorised in either direction on the GWML for the accelerated trains.

The pairs of 37s didn't last long, 47s were substituted after about a year with no change to timings. Schedules were then eased by 5 mins soon after.

 

[Merle Haggard]

No re-gearing, that's a myth.

As built all of 37s, 50s and 55s shared the same bogie design and gearing (106mph continuous on mid-life tyres).

The background was presumably a desire to accelerate the best business trains, two sections of 100mph were authorised in either direction on the GWML for the accelerated trains.

The pairs of 37s didn't last long, 47s were substituted after about a year with no change to timings. Schedules were then eased by 5 mins soon after.

Thanks. The reason for the re-gearing suggestion was that it was only a small batch of he class that worked the services (very highest 6900s and maybe the 6600s, from memory) but that was probably just because they were the newest. Although the 100 mph stretches were limited, I would guess that acceleration was impressive!

 

[hexagon789]

Thanks. The reason for the re-gearing suggestion was that it was only a small batch of he class that worked the services (very highest 6900s and maybe the 6600s, from memory) but that was probably just because they were the newest. Although the 100 mph stretches were limited, I would guess that acceleration was impressive!

It was more that the allocated locos were given special maintenance for the demanding running, the pool was D6875-6892.

The idea for accelerated 100mph timed services developed when the 'famous' Gerry Fiennes was general manager of the Western Region, though only came to fruition the year after his tenure ended; a test run was made in 1964 to prove the theory.

The accelerated schedules on selected trains were launched on the 18th of May 1966, other trains remained officially limited (and timed) for 90mph.

Two carriage sets were provided, one was the XP64 set and the other a freshly overhauled all-Blue/Grey Mk1 set on Commonwealth bogies.

The XP64 was usually used on the 0820 SWA-PAD, 1245 PAD-BRI, 1615 BRI-PAD & 1900 PAD-SWA, with the Mk1 set running the 0845 PAD-BRI, 1115 BRI-PAD, 1445 PAD-BRI & 1815 BRI-PAD.

100mph sections were MP 11 to MP 29.5 and MP 43 to MP 63.75 on the Down Main and MP 63.75 to MP 43.75 and MP 43.25 to MP 10 on the Up Main.

Brush Type 4s appear to have mostly taken over by January 1967, which was earlier than I had remembered.

 

[Merle Haggard]

It was more that the allocated locos were given special maintenance for the demanding running, the pool was D6875-6892.

The idea for accelerated 100mph timed services developed when the 'famous' Gerry Fiennes was general manager of the Western Region, though only came to fruition the year after his tenure ended; a test run was made in 1964 to prove the theory.

The accelerated schedules on selected trains were launched on the 18th of May 1966, other trains remained officially limited (and timed) for 90mph.

Two carriage sets were provided, one was the XP64 set and the other a freshly overhauled all-Blue/Grey Mk1 set on Commonwealth bogies.

The XP64 was usually used on the 0820 SWA-PAD, 1245 PAD-BRI, 1615 BRI-PAD & 1900 PAD-SWA, with the Mk1 set running the 0845 PAD-BRI, 1115 BRI-PAD, 1445 PAD-BRI & 1815 BRI-PAD.

100mph sections were MP 11 to MP 29.5 and MP 43 to MP 63.75 on the Down Main and MP 63.75 to MP 43.75 and MP 43.25 to MP 10 on the Up Main.

Brush Type 4s appear to have mostly taken over by January 1967, which was earlier than I had remembered.

Thanks for all the info' - I now do remember the number series, it did seem a bit randomly chosen. Can't believe it was nearly 60 years ago, though. About 1968 I caught the overnight Paddington West Wales via Gloucester service and it included an XP64 coach (still with rather stiff double hinged doors), so their fall from grace was rapid - that train also included G.W. design stock with the non-slam locks, quite choice selection.

 

[hexagon789]

Thanks for all the info' - I now do remember the number series, it did seem a bit randomly chosen. Can't believe it was nearly 60 years ago, though. About 1968 I caught the overnight Paddington West Wales via Gloucester service and it included an XP64 coach (still with rather stiff double hinged doors), so their fall from grace was rapid - that train also included G.W. design stock with the non-slam locks, quite choice selection.

Before it transferred to the WR, the XP64 was used on the Talisman on the ECML - another demanding fast service.

So yes, it appears to have briefly been BR's flagship coaching stock then rapidly sidelined as the Mk2s came on stream.

 

[Harpo]

I now do remember the number series, it did seem a bit randomly chosen.

Boilered locos for train heating.

 

[Merle Haggard]

Boilered locos for train heating.

Thanks, overlooked that.

 

[70014IronDuke]

No re-gearing, that's a myth.

Thank goodness you said it. I was beginning to think, as it's been said so often, that it was true, when I was sure it had been debunked decades ago.

The pairs of 37s didn't last long, 47s were substituted after about a year with no change to timings. Schedules were then eased by 5 mins soon after.

I definitely remember it was 1966, but I thought these workings only lasted until about September.

The talk at Landore was that the Cl 37s tended to struggle to get above 90 mph, due to the back EMF effect. Coupled with the extra fuel costs and wear and tear on the locomotives (rather like the double-headed Warship experiment on Plymouth trains later) the time savings were ultimately considered not worth it - though I'm sure the savings must have been significant on the stop-start section between Cardiff and Swansea - not to mention the ability to climb the bank between Swansea and Neath.
But the time savings on that section would not be of the same value as cuts in the Cardiff - Pad schedules.

 

[hexagon789]

Thank goodness you said it. I was beginning to think, as it's been said so often, that it was true, when I was sure it had been debunked decades ago.

As with many statements over the years, so you have to go back to original sources etc.

In this case it's quite straightforward though - the 37s original had 106mph geared bogies and many preserved, 100mph mainline passed Deltics have gained these bogies in preservation...

The talk at Landore was that the Cl 37s tended to struggle to get above 90 mph, due to the back EMF effect. Coupled with the extra fuel costs and wear and tear on the locomotives (rather like the double-headed Warship experiment on Plymouth trains later) the time savings were ultimately considered not worth it - though I'm sure the savings must have been significant on the stop-start section between Cardiff and Swansea - not to mention the ability to climb the bank between Swansea and Neath.
But the time savings on that section would not be of the same value as cuts in the Cardiff - Pad schedules.

A lot of the running times were very tight, with little margin for recovery.

Nevertheless on one of the original 1964 test runs, one of the test trains is quoted as having accelerated from 58 to 93mph in 1.5mi on the level and gone on to achieve a maximum of 103mph and holding 100 or so for about 13 miles without issue, so I'm not sure how poor the performance was assuming those details are correct.

 

[Taunton]

I saw these trains once, it gets mentioned in my account of the Newton-le-Willows to Newton Abbot Motorail in 1966. On the northbound return we left Newton Abbot some time after 1500, and were stopped at Filton junctions for (eventually) such a Down South Wales express to take precedence down into the Severn Tunnel. Probably around 1800 by then, doesn't align with the timings above but doubtless there were variations.

The double headed power would also have been very good at getting from the Severn Tunnel bottom up to Patchway, and equally beyond up to Badminton.