ScotRail (National Express) slam-door multiple units - Classes 101, 117 & 305

[hexagon789]

The climb from Barrhead to Shilford works the Class 156 sets hard, so I'm not at all surprised ! I wonder how long it took the set (3 cars but only 1 power car) to get to Kilmarnock ?

Sadly unrecorded, but I would doubt it made 70 except downhill but I think uts mostly uphill from Barrhead to Kilmarnock?

 

[TheSel]

Three car Met Cam (101) / Derby (107) set '101304' (51224 nearest the camera) at Barrhill one evening in May 1986. Scanned from my own slide.

 

[hexagon789]

Three car Met Cam set 101304 (51224 nearest the camera) at Barrhill one evening in May 1986. Scanned from my own slide.

View attachment 105813

That's a 107 car at the back.

 

[TheSel]

So it is - well spotted!

Caption corrected. Many thanks.

 

[hexagon789]

So it is - well spotted!

Caption corrected. Many thanks.

Very common at this time as well, there's a photo on Flickr where a set was formed of two 101 driving motor brakes sandwiching a 107 trailer; i often wonder if mixed sets were more common than single class sets! The fact that the whole set is in SPT livery despite the 107 car is also something in itself, often the liveries get mixed when a vehicle off a different class appears, but it certainly goes to prove the soundness of the Blue Square DMU concept - very versatile.

 

[alangla]

A power twin class 101 could keep to Sprinter schedules no problem.

I guess I was tending to use them on inner suburban routes that had lots of stops close together. Either that or the high revving of the 156 on starting away made it feel faster.
One thing I’ve often wondered about the 101s, especially from looking over the driver’s shoulder when the blinds were open: IIRC, they had a fairly narrow power band marked on the rev counter, but every upshift seemed to result in the revs dropping right back out of the power band. If they’d had 6 speed boxes instead of 4 (?) would they have been able to accelerate significantly faster?

 

[seagull]

Often think it's a huge shame that no UK trains have the forward (or backward) viewing windows these days - particularly on the more scenic routes. If it weren't for my trips on these heritage DMUs and the fascinating view forward and seeing the driver in action when I was young it's quite possible my interest in trains and railways would never have been kindled.

 

[alangla]

Often think it's a huge shame that no UK trains have the forward (or backward) viewing windows these days - particularly on the more scenic routes.

If I had a time machine, I’d love to go back to the early 80s and enjoy a front seat ride in an unrefurbished 303 or a 311 to Helensburgh, Gourock or Wemyss Bay. Even the Cathcart Circle and the city centre tunnels would be fascinating from that viewpoint.

 

[Bikeman78]

I guess I was tending to use them on inner suburban routes that had lots of stops close together. Either that or the high revving of the 156 on starting away made it feel faster.
One thing I’ve often wondered about the 101s, especially from looking over the driver’s shoulder when the blinds were open: IIRC, they had a fairly narrow power band marked on the rev counter, but every upshift seemed to result in the revs dropping right back out of the power band. If they’d had 6 speed boxes instead of 4 (?) would they have been able to accelerate significantly faster?

Yes the first gen DMUs had four gears. You're probably right about the 156s. I never timed a 101 from 0 to 60. Did you ever go on the four speed Ailsa buses in Glasgow? I always thought they sounded like a class 101 on steroids. Sounded similar and whizzed up through the gears.

If I had a time machine, I’d love to go back to the early 80s and enjoy a front seat ride in an unrefurbished 303 or a 311 to Helensburgh, Gourock or Wemyss Bay. Even the Cathcart Circle and the city centre tunnels would be fascinating from that viewpoint.

Yes the 303s must have been great fun with the forward view. I only remember them in their refurbished condition. I had a few runs on a 312 out towards Colchester with the blinds up but the saloon windows were quite high so I had to kneel on the front seat or stand up.

 

[hexagon789]

I guess I was tending to use them on inner suburban routes that had lots of stops close together. Either that or the high revving of the 156 on starting away made it feel faster.
One thing I’ve often wondered about the 101s, especially from looking over the driver’s shoulder when the blinds were open: IIRC, they had a fairly narrow power band marked on the rev counter, but every upshift seemed to result in the revs dropping right back out of the power band. If they’d had 6 speed boxes instead of 4 (?) would they have been able to accelerate significantly faster?

Because power had to be shut off for each gear change and when reapplied would pick up at the lower end and slowly build towards max revs until the next change came up? I'm probably not explaining that very well, I know what I mean to convey in my head - but putting it into words...

I never timed a 101 from 0 to 60.

There's an article on 101 performance in one of the RAIL Express 0-60 columns, and I believe there's a graph on railcar showing expected performance in terms of acceleration time against engine revs/road speed

 

[nw1]

It was the reintroduction of services to Barrhead, Maryhill, Whifflet, Paisley Canal, Motherwell to Cumbernauld in the early 1990s that reintroduced the need for heritage units around Glasgow and the falling through of the class 157 order. Ultimately, the 170 > 158 > 156 > 101 cascade allowed their withdrawal.

Presumably 117s around Edinburgh arose because there weren't enough 150s for the peak capacity - the 150s themselves being seen off by the later 170s.

Interesting to learn about the units on some of these services. I did use the Fife line once in 1993 (to Leuchars) and it appeared to be 150-operated then; didn't realise until now that it later got heritage units during the peak.

 

[Galvanize]

Used to see both the ScR 117 and 305s in the Edinburgh area from the train when going to/from the Grandparents in Dundee, though sadly never got the chance to do either. My Granddad did take a few photos of the 305s, seen a few while going through his old photos.

I believe WAGN 317s were earmarked to replace the 305s in the late 90s with the problems surrounding introducing the 334s meaning 318s couldn’t be displaced in time…at least one of the magazines mentioned it was on the cards. 322s arrived instead, the first time around in late 2001/early 2002, as WAGN couldn’t afford to lose 4 or 5 317s when they were sweating them enough as it was!

I recall one rather frustrated person wrote into RAIL magazine expressing their anger about valuable Sliding Door EMUs being pinched from WAGN to replace the 305s, his suggestion was the slightly younger Class 310s should have replaced the 305s until suitable stock became available!

 

[GusB]

Because power had to be shut off for each gear change and when reapplied would pick up at the lower end and slowly build towards max revs until the next change came up? I'm probably not explaining that very well, I know what I mean to convey in my head - but putting it into words...

I'm probably not going to be able to explain it any better from a technical standpoint, but the SCG/Wilson-type epicyclic gearboxes that were used in DMU and bus transmissions relied on having the power shut off during gear changes so as not to risk having more than one "gear" engaged at the same time (something to do with "brake bands").

I'll leave it to those with more in-depth knowledge to explain (in a separate thread, preferably) why exactly this is, but "slamming" through the gears without lifting your foot off the throttle in road vehicles was frowned upon. Fully automatic versions of such transmissions had a mechanism that cut off the fuel supply during gear changes.

 

[Bikeman78]

I'm probably not going to be able to explain it any better from a technical standpoint, but the SCG/Wilson-type epicyclic gearboxes that were used in DMU and bus transmissions relied on having the power shut off during gear changes so as not to risk having more than one "gear" engaged at the same time (something to do with "brake bands").

Occasionally a driver would fly through the gears on a 1st gen DMU, rather than let the revs drop all the way down. I've no idea what this did to the gearbox although the unit in question always made it to destination on the occasions that I saw it happen.

 

[hexagon789]

I'm probably not going to be able to explain it any better from a technical standpoint, but the SCG/Wilson-type epicyclic gearboxes that were used in DMU and bus transmissions relied on having the power shut off during gear changes so as not to risk having more than one "gear" engaged at the same time (something to do with "brake bands").

Makes sense, I've seen the gearbox in operation in a training video (probably still available on YouTube) and I remember seeing how these callipers gripped a thick band round each geartrain to engage it. From memory fourth gear was all locked together, one of the reasons coasting could only be done in fourth.

Occasionally a driver would fly through the gears on a 1st gen DMU, rather than let the revs drop all the way down. I've no idea what this did to the gearbox although the unit in question always made it to destination on the occasions that I saw it happen.

The manual suggests damage will occur, but perhaps it requires very harsh repeated treatment in that manner.

Nevertheless, there were incidents where a mechanical unit was not changed up through the gears correctly, because it was being worked with with hydraulic set, and the driver forgot about the mechanical unit on the back so drove in the automatic setting and promptly wrecked the mechanical sets gearbox. This is the reason for the decision to no longer permit the 127s to multi with mechanical sets even though electrically it was still possible.

 

[Bikeman78]

Nevertheless, there were incidents where a mechanical unit was not changed up through the gears correctly, because it was being worked with with hydraulic set, and the driver forgot about the mechanical unit on the back so drove in the automatic setting and promptly wrecked the mechanical sets gearbox. This is the reason for the decision to no longer permit the 127s to multi with mechanical sets even though electrically it was still possible.

I didn't know that the 127s had different transmission as they finished before I went up the MML. Was it similar to class 150 transmission?

 

[hexagon789]

I didn't know that the 127s had different transmission as they finished before I went up the MML. Was it similar to class 150 transmission?

Two-speed hydraulic, so not entirely unlike a Sprinter, rather than 4-speed mechanical. They were specifically designed that way to give them EMU-like performance, hence the 238bhp Rolls-Royce engines rather than the standard 150hp AEC or Leyland ones.

Electrically they were Blue Square as per the standard mechanical units, they had a gear selector lever as per the mechanical sets but marked '1', '2', '3' and the 'D' in place of '4'. 'D' stood for 'Drive' and the selector was left in this position ordinarily unless coupled to a mechanical set in which case the gear changes needed to be made as per usual and 'D' equated to 4th gear.

 

[Bikeman78]

Two-speed hydraulic, so not entirely unlike a Sprinter, rather than 4-speed mechanical. They were specifically designed that way to give them EMU-like performance, hence the 238bhp Rolls-Royce engines rather than the standard 150hp AEC or Leyland ones.

Electrically they were Blue Square as per the standard mechanical units, they had a gear selector lever as per the mechanical sets but marked '1', '2', '3' and the 'D' in place of '4'. 'D' stood for 'Drive' and the selector was left in this position ordinarily unless coupled to a mechanical set in which case the gear changes needed to be made as per usual and 'D' equated to 4th gear.

Interesting, thanks. So the driver simply put the power handle to max and let the unit get on with it? With almost 1000hp they must have been capable of rather more than 70 mph.

 

[hexagon789]

Interesting, thanks. So the driver simply put the power handle to max and let the unit get on with it? With almost 1000hp they must have been capable of rather more than 70 mph.

Fear selector to 'D', then fully open the throttle. The convertor operated up to 46mph at which point the transmission switched to Direct Drive. Interestingly I've since read that until the early 1970s the transmission fluid was originally fuel oil (ie diesel)! Before being changed to a specific hydraulic fluid, because using diesel was found to be a fire risk!

Yes, at about 7bhp per tonne weight - not very different to a Sprinter so they probably were quite capable at that, though the few references to speed only show maxima within a few mph tolerance of their 70mph design speed.