Scalefour Forum

Hi all

I found this video of what to my eye looks quite a handsome single car unit

And it got me thinking. This has a very loco-ish face. Was there a reason most DMUs in the uk didn’t follow the small cab window approach of locos and had very large windows. Likewise was there a reason locos didn’t have large windows? As a guess is it because locos were expected to shunt stuff about and DMUs (generally) weren’t or is just a coincidence?

As an aside there’s a few examples of some quite iffy track in the video.

Cheers

Jim

jim s-w wrote:And it got me thinking. This has a very loco-ish face. Was there a reason most DMUs in the uk didn’t follow the small cab window approach of locos and had very large windows. Likewise was there a reason locos didn’t have large windows? As a guess is it because locos were expected to shunt stuff about and DMUs (generally) weren’t or is just a coincidence?

As a wild speculation, in a diesel predominant/only environment, a far lower chance of gaining a large chunk of anthracite through the glazing at 30mph!

Plus, tradition... Don't underestimate the power of "but that was how we were building them in 1860...".


Cheers
Flymo

jim s-w wrote:
.........As an aside there’s a few examples of some quite iffy track in the video.

Here's some iffy track for you Jim and an interesting shunting move! https://www.youtube.com/watch?v=WznzgvP9cts

Ooh, like that running round method!

Autocoach design gives a precedent. Off the top of my head the only loco-inspired autocoach designs were the NE porthole vehicles, which always looked a bit odd to me. The first generation of MUs (and their successors) looked to have been influenced by contemporary bus design.

There is also marketing to consider. DMUs were marketed as a modern, sparkly replacement for the smelly, life-expired, cascaded carriages on secondary services, and the bright contemporary design elements were part of this. I think this also accounts for the huge panes of glass in the bulkheads between passengers and driving compartment. It was a tremendous innovation to be able to get a driver's-eye view of the road and brought a lot of publicity at the time. Because of the novelty, my grandfather used a lot of precious 8mm cine film on his first DMU trip, and as a student in Aberystwyth it was always great to get a front row seat for the trip over the Cambrian mountains.

One of the explanations for the smaller diesel loco windows must be that the cab floor was higher up so the eyeline to roofline distance was shorter, but also there was no need to market to footplatemen who were (we hope) already used to seeing where they were going.

In retrospect I could just have written the word "marketing" and saved myself some time.

It was a tremendous innovation to be able to get a driver's-eye view of the road and brought a lot of publicity at the time

And wasn't it annoying when the driver pulled the blinds down
What I always found strange was that contemporary EMUs never followed the same concept, and it's vanished since except on the DLR where the front seats are very popular.
Regards

Nottingham Trams also have front seats but annoyingly put the doors there too, so people tend to stand in the way. One of the reasons for the nose and smaller windows was sleeper flicker which was said to cause distraction to drivers. Did/do GWR railcars have a view from the passengers? I've seen them but never been inside. They have nice big windows too !

grovenor-2685 wrote:And wasn't it annoying when the driver pulled the blinds down

Yes! If my memory doesn't deceive me, when DMUs were first introduced it was exceptional for the blinds to be pulled down, but as time passed the practice was adopted ever more frequently, until it became exceptional instead for a passenger to be able to get a view of the line ahead. I can, however, recall a post-1965 DMU trip over the Devizes branch when I was fortunate enough to have such a view throughout.

I'm not convinced that the propulsion method had anything to do with big windows being provided for the driver. Look at some Sentinel steam railcar designs and you will see front ends very similar to those of a DMU. And in the case of the steam locomotive, the conventional arrangement of having the driving position behind the boiler effectively precluded provision of large windows. When the 'cab forward' approach was adopted you could see cabs provided with substantial forward facing windows; e.g. the Southern Pacific's AC-12 class 4-8-8-2s.

The 1959 film Diesel trainride shows the marketing aspect. Part of the BFI Transport Films Collection.

That was some DMU journey. GER East Anglia to Wales? via the North Eastern. Were they McKenzie and Holland signals at the end?

Hardwicke wrote:That was some DMU journey. GER East Anglia to Wales? via the North Eastern. Were they McKenzie and Holland signals at the end?

The gents at 7:00 are consulting their map in an attempt to fathom how they have been magically transported from East Anglia to Wetheral on the Newcastle & Carlisle Railway!

I was amused by the apparent subtle differences in the attitude to track side safety for the track maintenance gangs.

Very typical GER hills. Like the MS&LR. No money for earthworks !

The one scene looked like Blencathra.

Is there anything in the story that the full depth windows caused photo-hypnotic effects in the driver from the sleepers flashing closely below?

But the driver needed to see a little old lady waving her handkerchief:

https://www.independent.co.uk/travel/uk ... 46846.html

Martin.

philip-griffiths wrote:The one scene looked like Blencathra.

Nah, its the Gog Magog near Cambridge (which is slightly off-route for Norwich). If you get the camera angle right, it can look a bit like the lake district

Martin Wynne wrote:Is there anything in the story that the full depth windows caused photo-hypnotic effects in the driver from the sleepers flashing closely below?

So far as I know, there were no visible measures taken at the time to reduce any such risk, so presumably not. A driver's attention whilst the train is moving is usually focussed as far away as possible in front of the train, looking for signals and potential hazards.

Noel wrote:

Martin Wynne wrote:Is there anything in the story that the full depth windows caused photo-hypnotic effects in the driver from the sleepers flashing closely below?

So far as I know, there were no visible measures taken at the time to reduce any such risk, so presumably not. A driver's attention whilst the train is moving is usually focussed as far away as possible in front of the train, looking for signals and potential hazards.

But I'm sure I read somewhere that the smaller windows on later stock were to reduce such risks. On the other hand, if no measures were taken to block off the lower part of the big windows, it can't have been taken very seriously. But it would likely be related to the designed line speed.

Martin.

I have heard the sleeper flicker effect used as a reason for the long noses on some diesel such as class 40 or Deltic.
Small windows were more of a driver safety issue as they allowed much stronger glass to cope with missiles, bricks dangling off bridges etc.
Rgds

The Deltic nose did allow fitting of the crew loo and washbasin - don't think that was what 'drove' the design, though ...

grovenor-2685 wrote:I have heard the sleeper flicker effect used as a reason for the long noses on some diesel such as class 40 or Deltic.

I remember reading about the sleeper flicker effect as a youthful trainspotter Keith but having been a train driver for the last 19 years on classes 08, 56, 60, 66 and 67 I can’t say I’ve ever found it to be a real thing.

Martin Wynne wrote:it can't have been taken very seriously. But it would likely be related to the designed line speed.

The fastest rail motive power in the mid- to late-1960s were the West Coast electrics, all with sloped fronts but no extended noses. There were plenty of high-speed diesel classes with more or less flat fronts as well: D800 series Warships, Westerns, Class 47 (as they became), and most Type 2 or Type 3 classes.

Back in the early 60's there was a bit of an epidemic of British drivers in France running off the road or into a tree, having apparently fallen asleep. It was eventually concluded that the constant flicker caused by the trees at the sides of the road could be close enough to a natural frequency in the brain to cause loss of consciousness. The frequency was about 7Hz. I believe there was some problem about flying helicopters at night for the same reason. Sleepers passing under a train are unlikely to be at 7Hz (about 11 mph)


Allan F

dal-t wrote:The Deltic nose did allow fitting of the crew loo and washbasin - don't think that was what 'drove' the design, though ...

It was actually a standard EE design based on American practice at the time. During our research into the new 10000 www://lms10000.co.uk we found that the toilet in the nose had been wired to some electrical lead. Bit shocking, literally. It was discovered before leaving Derby Works !