126 DMUs on Western Region

[MidlandRed]

8 minutes ago, keefer said:

Think that's the only time I've seen speed whiskers on a gangway cover!

Excellent pics Robert.

 

The WR parcels cars (55991-6) also had this arrangement of speed whiskers  - until the door covers became yellow. The class 123s had yellow door covers from new (quoted in some books as being an element of the Design Panel input to the class 123). 

[keefer]

2 hours ago, keefer said:

Forgot all about the lack of jumpers on the end DM, another odd feature of these units.

There were also instructions in the General Appendix regarding coupling to these units in an emergency - they were not lightweight units but they were classed as having lightweight buffing gear so restrictions applied.

I'll see if I can get them scanned.

Was talking out my backside I'm afraid!

Had a quick look through and the instructions seem to be mainly about coupling vehicles together, or with other vehicles fitted with buckeyes, or using screw couplings in an emergency - i.e. whether buffers are retracted/extended and which coupling is used etc.

Unless I can find anything that says otherwise, I must've been mistaken re: the lightweight buffing gear - possibly getting mixed up with another DMU class.

[EddieK]

On 18/10/2019 at 19:20, The Johnster said:

The mk1 derived Class 123 Swindon Inter City 4 car units, the ones with wrap around windows similar to the Clacton 25kv electrics but not with the Commonwealth bogies, were introduced in 1962, with gangways between sets enabling 8 or 12 car trains with one Buffet; these had more powerful engines and were geared for 75mph running.  

The top speed of 75mph would have made them incompatible with every other DMU class. I think their top speed was 70mph, as on all other classes with that power equipment such as 115 and 124. 

 

Despite the 70mph top speed, they must have been able to keep to their booked timings. An analogy relates to the use of 110mph Class 90 electrics on ECML in place of 125mph Class 91s. The 90 has the edge in acceleration and can hold its own against the timings (they were used on Leeds services that had a number of intermediate stops).

 

Returning to 123s, there is of course the possibility that a driver in a hurry may have exceeded 70mph...

[russ p]

In the early 2000s when central trains had 170s a lot of drivers when on the ECML used to leave power on and the overspeed regulator would keep the speed between 102 and 98mph , 5this was fine .... until he got to Ely and changed ends to find a 156 on the back!

The driver he relieved didn't tell him it was there and the young guard thought the driver knew what he was doing so also didn't say anything 

[SRman]

51 minutes ago, russ p said:

In the early 2000s when central trains had 170s a lot of drivers when on the ECML used to leave power on and the overspeed regulator would keep the speed between 102 and 98mph , 5this was fine .... until he got to Ely and changed ends to find a 156 on the back!

The driver he relieved didn't tell him it was there and the young guard thought the driver knew what he was doing so also didn't say anything 

I might be talking through my hat here, but wouldn't the 156 have just been free-wheeling at those speeds?  I know there were regulations for Southern Region EMUs that allowed 75 mph units to be run at 90 mph without detriment when attached to suitably geared units, as long as more than two-thirds of the powered axles were geared for 90 mph. Of course, the transmissions are completely different between DMUs and EMUs, so maybe someone with more knowledge of such DMUs might be able to clarify a bit.

[russ p]

The 156 wouldn't have been doing much as the maximum speed of the transmission had been exceeded and was been pulled along by the 170. Whatever it's not the greatest place for it to be

[The Stationmaster]

13 hours ago, keefer said:

Was talking out my backside I'm afraid!

Had a quick look through and the instructions seem to be mainly about coupling vehicles together, or with other vehicles fitted with buckeyes, or using screw couplings in an emergency - i.e. whether buffers are retracted/extended and which coupling is used etc.

Unless I can find anything that says otherwise, I must've been mistaken re: the lightweight buffing gear - possibly getting mixed up with another DMU class.

Lightweight buffing gear sounds like one of the railbus classes.  All the DMUs had standard drawgear of one sort or the other.

 

Incidentally the 123s - on which I travelled regularly commuting to/from Paddington had no trouble at all maintaining running times provided an engine didn't drop out (of use).  And judging by my trip on one to Minehead and back they didn't have any problem keeping time on longer distance journeys either.  they were however not quite so quick off the mark on all stations workings hence they very rarely appeared on succh trains when allocated to Reading.

[Clive Mortimore]

57 minutes ago, The Stationmaster said:

Lightweight buffing gear sounds like one of the railbus classes.  All the DMUs had standard drawgear of one sort or the other.

 

Incidentally the 123s - on which I travelled regularly commuting to/from Paddington had no trouble at all maintaining running times provided an engine didn't drop out (of use).  And judging by my trip on one to Minehead and back they didn't have any problem keeping time on longer distance journeys either.  they were however not quite so quick off the mark on all stations workings hence they very rarely appeared on succh trains when allocated to Reading.

A large number of ER units had "LW" on their blue square coupling code markings as a precaution sign reminding staff that they had light weight buffering gear.

[MJI]

I have seen the rev counter of a DMU buried in the red and the speedo was nearing 90, it felt like it too.

 

Not sure on class, but would have to be 101, 117,  118, 119, or 120

[The Johnster]

9 minutes ago, MJI said:

I have seen the rev counter of a DMU buried in the red and the speedo was nearing 90, it felt like it too.

 

Not sure on class, but would have to be 101, 117,  118, 119, or 120

IIRC the speedo on 1st generation dmus only went up just past 70mph, the 'official' top speed and what the trains were geared for, but I've certainly ridden on them at well above that on 2 occasions with 116s, not what you'd normally associate with this sort of adventure...  One was the empty stock off the 'last Aber', empty from Aber Jc to Canton CS on a New Year's Eve with a driver who wanted to make last orders at the pub near Canton shed, the Craddock.  Speed down the bank was probably in the 90mph ball park. line speed on this section; he shut off power at the Wedal Road bridge, applied brakes at Crwys Road bridge, and obeyed all PROS completely, a superb demonstration of his mastery of the job.  On another occasion, I travelled to Swindon on the cushions with a driver to pick up a single DMS from the works to run ecs to Canton.  This had the speedo needle on the stop for most of the journey and was probably around the 80mph mark.  

 

On both occasions I was impressed by the ride, which was nowhere near as bad as I thought it might be, and the effectiveness of the brakes.  Mike The Stationmaster mentions engines dropping out on the 123s, which were prone to it for some reason, but it was a not uncommon thing on all our dmus at Canton in the 70s, and the very hot summer of 1976 was very tough on them as the coolant failed to keep the engines cool and they persistently cut out automatically from overheating.  I recall going off shed with only 2 engines working on Valley services and crossing fingers that another one wasn't going to drop out; we failed one set at Caerphilly having come off shed with 3 engines working, and lost 2 of those on the way up the bank.  We had a struggle to get away from Llanishen in first gear with 2 and one dropped out almost as soon as the train cleared the platform, and we were very late at Caerphilly.  We struggled on empty to Aber with the following service close behind and crossed over to go home.  Dmus were like the little girl with the little curl; when they were good they were very very good but when they were bad (most of the time) they were 'orrid.

 

123s were slower off the mark because of the gearing, but not too bad on the banks, presumably because of the smaller wheel diameter of the B4 bogies.  They rode very well, as did all B4 fitted stock, and seemed to have better insulation from engine noise and vibration.

[MJI]

My main DMU routes were from Gloucester to Worcester & Birmingham or Swindon.

 

The fast run was to Swindon and the needle was well past 70.

 

Done  a few South Wales routes, AFAIR all 116 with corridors, rode on a last year of 116 with 2 power cars and they were power shifting it rather than the 4 second change 3 second rule.

 

I also remember being on a Tyseley 116 and getting annoyed at the long bench at the end of the car. And also the extra seats in the middle of the trailer. Definately prefered 117 and 118.

 

Very sad how little 116 118 119 120 preserved.

[The Johnster]

Sounds about right.  116s were designed for high intensity general use and did not have the large first class saloons of 117/8 sets or the central toilet compartments.  These sets were designed for London area outer suburban commuter services, which feature more demand for first class accommodation and journey lengths (Paddington-Oxford, Paddington-Newbury) thad required toilet facilities.  They were better 'appointed' in general.  117/8s migrated to the Bristol and later Cardiff Valleys services later in their lives.  The gangways and toilets made them suitable for long distance work, and Bristol-Weymouth was common; by the mid 70s they were regarded as interchangeable with Cross Countrys on the WR.  All sets were built without gangway connections, which were fitted to the WR sets when unstaffed stations and conductor guards were introduced in the 60s, and non-WR sets such as the Lea Valley trains retained the full width compartment dividers and end benches, as did the Marylebone and St Pancras Bed-Pan 4 car sets.  As a very sweeping generalisation and not a 100% accurate guide, blue livery = gangways on the WR but not elsewhere, and blue/grey and 'refurbished' = gangways everywhere.

[EddieK]

Perhaps the lethargy of Class 123s when pulling away was down to their solid construction. The Class 115s at Marylebone / Allerton had similar traction equipment and their motor vehicles weighed 38 tons, with trailers around 29 tons. On the Class 123, the motor vehicles weighed 41 tons and the trailers 31 or 32 tons. 

[royaloak]

13 hours ago, EddieK said:

The top speed of 75mph would have made them incompatible with every other DMU class. I think their top speed was 70mph, as on all other classes with that power equipment such as 115 and 124. 

 

How so?

The top speed is not really relevant as long as the train is driven correctly and the maximum speed is that of the slowest vehicle.

[royaloak]

13 hours ago, russ p said:

In the early 2000s when central trains had 170s a lot of drivers when on the ECML used to leave power on and the overspeed regulator would keep the speed between 102 and 98mph , 5this was fine .... until he got to Ely and changed ends to find a 156 on the back!

The driver he relieved didn't tell him it was there and the young guard thought the driver knew what he was doing so also didn't say anything 

Quite a common occurrence, luckily I never did it when driving a 158 with a 153 on the back, nope never!

[EddieK]

To the best of my knowledge, all first generation DMUs had a consistent maximum speed of 70mph. Presumably designed as such so that there was no possibility of confusion over the speed of the slowest vehicle.

[royaloak]

5 minutes ago, EddieK said:

To the best of my knowledge, all first generation DMUs had a consistent maximum speed of 70mph. Presumably designed as such so that there was no possibility of confusion over the speed of the slowest vehicle.

True, but some had hydraulic transmission meaning they were driven differently, sometimes causing 'issues' with the mechanical unit on the back.

[EddieK]

Just now, royaloak said:

True, but some had hydraulic transmission meaning they were driven differently, sometimes causing 'issues' with the mechanical unit on the back.

Yes, I had that issue in mind when typing my previous item...!

[russ p]

That's why 127s were given red triangle multi working code. Apparently one was working with a cravens but the driver didn't change up and ended up doing 70mph with cravens in 1st gear!

[keefer]

Correct, they were actually Blue Square  - hence in later years some TS were used to supplement cl.116 units as there were no modifications necessary.

i.e. the Red Triangle code was just to distinguish them once they were the only hydraulic units left

Probably didn't help that there were D-H Cravens units (106 & 113?) as well as the normal mechanical ones, could easily cause confusion.

I think also there were enough problems with the hydraulic units themselves, never mind when mixing them with mechanicals.

Edited October 22, 2019 by keefer
For clarity

[caradoc]

In the early 1970s I occasionally travelled (if nothing better was available) on the Oxford-Paddington stopping trains, formed by Class 117 (or as we called them then, Pressed Steels); I recall crossing over at Dolphin Jc, east of Slough, from Up Relief to Up Main and showing a fair turn of speed to Paddington ! This was before 125mph trains on the WR, of course.....

Edited October 22, 2019 by caradoc
GWR track naming corrected

[Clive Mortimore]

3 hours ago, russ p said:

That's why 127s were given red triangle multi working code. Apparently one was working with a cravens but the driver didn't change up and ended up doing 70mph with cravens in 1st gear!

Hi Russ

 

The problem was Cricklewood had both 112s and 113s allocated to it and if it was a 112 that was coupled to the 127 the driver would forget to throttle back so the 112 couldn't change out of first gear. 113s were fine coupled to a 127. As a driver how many of your work mates would take notice if the unit on the back had a headcode box on top or not?  Unless he was in the cab had had to change the headcode.  

[russ p]

Must have been a while back Clive?  I didn't realise it was one of those cravens,  I hadn't realised they were allocated there always thought they were in the north west 

[keefer]

Entry for cl. 112/113 at railcar.co.uk:

https://www.railcar.co.uk/type/class-112/

Says they were withdrawn by 1969

[Clive Mortimore]

14 minutes ago, russ p said:

Must have been a while back Clive?  I didn't realise it was one of those cravens,  I hadn't realised they were allocated there always thought they were in the north west 

 

3 minutes ago, keefer said:

Entry for cl. 112/113 at railcar.co.uk:

https://www.railcar.co.uk/type/class-112/

Says they were withdrawn by 1969

From my trainspotting days at Bedford it was about 1968/69 when the red triangle transfers were applied over the top of the blue squares on the 127s.

 

From the Railcar Association website 
 

Quote

 

Blue Square Becomes Red Triangle

The sets were delivered with the Blue Square coupling code, which allowed them to couple to any other Blue Square sets (which the majority were). However, the driver had to alter his driving technique when a Class 127 was coupled to a set with mechanical transmission, and the Class 127s had speedometers segregated into four parts to help with this.

Power could not be applied until the final drives were engaged properly. Selecting any gear put the set into 'drive'. There was trouble if the driver had a mechanical set at the back and forgot to change gear - any speed was possible in gear - causing major problems for the gearbox in the mechanical set. Apparently there was a plate in front of the driver which could be lifted to reveal a reminder (something like "Gearbox Stock"). 

As the sets worked their services exclusively, coupling to other units was a rare occurrence. However, when some Class 112 Cravens sets (Rolls Royce engines and mechanical transmission) were transferred to the Moorgate line, this did occur. On the 27th June 1968 a Class 127 coupled to one of these Cravens was travelling at high speed near St Albans when a gearbox seized and caused a serious fire, and was attributed to improper driving. While most of the Cravens were withdrawn in the five months following the incident, the rest were restricted to Kentish Town - Barking services. In 1969 the 127s were rebranded the Red Triangle coupling code to prevent such an event happening again, though there were no technical modifications done to justify their own code. As they were still wired for Blue Square, they would have been in no way compatible with the West Riding Derby Lightweights had they still been in service, which had originally carried the Red Triangle code.