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Deltic high speed trials on the the Western Region


TravisM
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Several Deltic's were used for the high speed trials on the Western Region in the mid to late 70's.  I believe they were trialled between Didcot and Swindon but I wonder what loco's and coaching stock used?  I know 55001 St Paddy was one of the loco's but I think two others (55020 maybe another?) were used.  Also was the coaching stock from the RTC or regular sets borrowed from local depots?

 

Julian Sprott

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Wasn't the high speed running carried out as a part of some 'dipped rail joint' testing IIRC?

 

 

Edit:

 

Couldn't open links Keefer posted when I wrote the above - wouldn't have needed the IIRC :)

Edited by leopardml2341
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Was it exhausting on one side only, which might imply one engine only running? Or, was it one engine running well, giving clear exhaust, and the other sick as a parrot and spewing out barely combusted stuff?

 

There are doubtless delticologists here who know better than I.

 

Kevin

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I know they're two-stroke engines, but isn't the idea to run them on fuel oil, not lubricating oil? Or is it simply emulating the oil consumption of an unrebuilt Bulleid pacific?

 

Either way, at least one engine really isn't in the best of health.

 

Jim

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Was it exhausting on one side only, which might imply one engine only running? Or, was it one engine running well, giving clear exhaust, and the other sick as a parrot and spewing out barely combusted stuff?

 

There are doubtless delticologists here who know better than I.

 

Kevin

 

Deltics carry over a lot of oil whilst idling, or on low power. This gets burnt off at high power. Once a Deltic has been running at full power for about 15 mins the exhaust will be crystal clear - in fact usually cleaner than other diesels as there is no trace of black or grey smoke due to the engines being de-rated by a substantial amount - Marine versions of the class 55 engine typically putting out 2,200-2,500bhp, turbo charged versions can do 3,200bhp, the charge cooled versions I think do even more!

 

This also means that the colour of the exhaust at any given time is no indicator of engine health, more an indicator of how long the engines have been idling. If they are left idling too long there can be sufficient carry over in the exhaust for it to catch fire once the engines are worked hard.

 

This is what it is like at west Ealing after presumably idling for a long time at Paddington - and the engines are quite healthy!

 

https://www.youtube.com/watch?v=qoktXA1VWHw

 

Originally on Class 55 the engines operated in unison, each power unit running at the same rpms and power, i.e. half power would mean both units working on half power. This changed when the Deltics were fitted with ETH. The ETH was taken from the main generator, and this could only provide the required volts when running at near full speed. To avoid ETH only being available at full power, the governors were arranged so that the power unit providing the ETH would spool up first. This meant that at half power you would have one power unit running flat out whilst the second was just idling. More power demand caused the second unit to spool up. It is why it might seem as a Deltic is pulling away that only one engine is running - one will be revving up and smoking whilst the other is still idling - until the controller is moved passed half power then the other unit starts to catch up with the first. Drivers were instructed not to use low power for long periods for this reason - less than half power for any length of time and the train would get cold!

 

To solve the problem of providing ETH at idle, the two generators were connected in series to get adequate volts.

Edited by Titan
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In his book, Gerry Fiennes describes how he tried to borrow a Deltic for trials on the WR in the 60s, but the "Rude Mechanicals" wernt having it, so he used double headed 37s on a trip to Plymouth. 

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Deltics carry over a lot of oil whilst idling, or on low power. This gets burnt off at high power. Once a Deltic has been running at full power for about 15 mins the exhaust will be crystal clear - in fact usually cleaner than other diesels as there is no trace of black or grey smoke due to the engines being de-rated by a substantial amount - Marine versions of the class 55 engine typically putting out 2,200-2,500bhp, turbo charged versions can do 3,200bhp, the charge cooled versions I think do even more!

 

This also means that the colour of the exhaust at any given time is no indicator of engine health, more an indicator of how long the engines have been idling. If they are left idling too long there can be sufficient carry over in the exhaust for it to catch fire once the engines are worked hard.

 

This is what it is like at west Ealing after presumably idling for a long time at Paddington - and the engines are quite healthy!

 

https://www.youtube.com/watch?v=qoktXA1VWHw

 

Originally on Class 55 the engines operated in unison, each power unit running at the same rpms and power, i.e. half power would mean both units working on half power. This changed when the Deltics were fitted with ETH. The ETH was taken from the main generator, and this could only provide the required volts when running at near full speed. To avoid ETH only being available at full power, the governors were arranged so that the power unit providing the ETH would spool up first. This meant that at half power you would have one power unit running flat out whilst the second was just idling. More power demand caused the second unit to spool up. It is why it might seem as a Deltic is pulling away that only one engine is running - one will be revving up and smoking whilst the other is still idling - until the controller is moved passed half power then the other unit starts to catch up with the first. Drivers were instructed not to use low power for long periods for this reason - less than half power for any length of time and the train would get cold!

 

To solve the problem of providing ETH at idle, the two generators were connected in series to get adequate volts.

 

Hence the fun that was had in Cowlairs tunnel with the Deltics on the sleepers!

 

Mike.

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Having heard on the grapevine that a Deltic might be seen there, I turned up at Didcot on one frosty Sunday morning in January 1975. I waited a few hours but saw nothing and went home. Does anyone know what time I should have been there?

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Andy, from the napier-chronicles link I posted above for 55007:

 

"12.01.75

On loan to Western Region for 'dipped rail joint tests' (permission to run L/E at 100 mph). Moves as follows:

5Zxx Didcot - Twyford.

5Zxx Twyford - Paddington.

5Zxx 06:30 Paddington - Didcot.

5Zxx 10:15 Didcot - (Willesden)

 

On Sundays 12th and 19th January 1975 a Deltic locomotive made high speed runs between Twyford and Didcot, hauling Mark IIe and If coaching stock and test coach Mentor. On 12th January 55007 "PINZA" was used whilst on the 19th it was the turn of 55001 "ST. PADDY".

 

On 12th January the locomotive was 55007 "PINZA" and was diagrammed as follows: dep. King's Cross 23:20 Sat night; arr. Didcot 01:45 Sun. Trials at speeds of 2, 30, 60, 90 and 100 mph until 05:00, return to Paddington for crew change 06:12-06:30 and return to Didcot until 10:00. The locomotive was due to depart Didcot at 10:15, arriving back at King's Cross for 12:44. However, the locomotive was noted at Willesden during the afternoon and it assumed the last part of the booked move was altered in some way."

Edited by keefer
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Having heard on the grapevine that a Deltic might be seen there, I turned up at Didcot on one frosty Sunday morning in January 1975. I waited a few hours but saw nothing and went home. Does anyone know what time I should have been there?

 

if it's anything like when I went looking for a particular locomotive, probably only 1 minute later (or earlier) !!

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