DMUs

Apologies for thread creep but in the steam photos is a shot of
Bahamas without its tender, the top of which seems to be on an
adjacent wagon.
I have a picture of Bahamas without its tender, taken at Farnley
junction (I recall the tender top being on an adjacent wagon), I guess
1963 ish. Was yours taken at Farnley, and do you know what the problem
was?

On Feb 26, 1:41 am, Pyromancer <pyroman...@beeching.stormshadow.com>
wrote:

> How common were the 2 car power-trailer sets?

That was the *normal* 2-car set up.

Some of the very very early BR Derby Lightweights were power twins,
while towards the end of DMU operations generally someone came up with
the bright idea of power twins (reliability mitigation) as if no-one
had heard of it before, but by far the main BR production and
operation of 2-car sets was DM+DT or multiples thereof.

--
Nick

On 26 Feb, 14:04, D7666 <d7...@m> wrote:
> On Feb 26, 1:41 am, Pyromancer <pyroman...@beeching.stormshadow.com>
> wrote:
>
> > How common were the 2 car power-trailer sets?
>
> That was the *normal* 2-car set up.
>
> Some of the very very early BR Derby Lightweights were power twins,
> while towards the end of DMU operations generally someone came up with
> the bright idea of power twins (reliability mitigation) as if no-one
> had heard of it before, but by far the main BR production and
> operation of 2-car sets was DM+DT or multiples thereof.
>
> --
> Nick

Why from the sprinter era onwards have all coaches been powered in
EMUs? What was performance of a power-trailer like compared to a
pacer or sprinter? Pretty poor I'd imagine, is the need to keep
improved timings the reason for power-twins in later years.

I wish I'd paid more attention to "heritage" DMUs in my youth, as well
as the rapidly declining loco-hauled trains.

On Feb 26, 2:59 pm, Nodding Donkey <floridsalo...@m> wrote:
> On 26 Feb, 14:04, D7666 <d7...@m> wrote:
>
> > On Feb 26, 1:41 am, Pyromancer <pyroman...@beeching.stormshadow.com>
> > wrote:
>
> > > How common were the 2 car power-trailer sets?
>
> > That was the *normal* 2-car set up.
>
> > Some of the very very early BR Derby Lightweights were power twins,
> > while towards the end of DMU operations generally someone came up with
> > the bright idea of power twins (reliability mitigation) as if no-one
> > had heard of it before, but by far the main BR production and
> > operation of 2-car sets was DM+DT or multiples thereof.
>
> > --
> > Nick
>
> Why from the sprinter era onwards have all coaches been powered in
> EMUs?  What was performance of a power-trailer like compared to a
> pacer or sprinter? Pretty poor I'd imagine, is the need to keep
> improved timings the reason for power-twins in later years.

They had more power per coach than a 150, so the power twins were
actually more powerful than a 150, although that wouldn't be all that
performance is based on.

I suppose a power-trailer DMU had about the same power per coach as a
33 plus ten (which one probably saw on boat trains etc).

>
> I wish I'd paid more attention to "heritage" DMUs in my youth, as well
> as the rapidly declining loco-hauled trains.

On 25 Feb, 20:41, Charlie Hulme <i...@davenportstation.org.uk> wrote:
> Brian Robertson wrote:

> > My friend says that they indicated some re gearing of the DMUs to cope with
> > the Buxton line.

> The gearing could not be changed, AFAIK. All had the same epicyclic
> gearbox. Whether they 'coped' with the Buxton line is a moot point.
> Ascent of the climbs could be somewhat slow, espcially with
> one or more of the 6 engines out of action ....

The gearbox(es) themselves were a standard Self Changing Gears
(Leyland Pneumocyclic) type of semi automatic, but AIUI the
_final_drive_ gearing could be varied. Indeed CIE had AEC/SCG BUT
DMUs(*) with two-speed final drives, so they would do around 40 mile/
hour on suburban stopping trains and 70 mile/hour on expresses.

(*)Sorry about all the TLAs.

I'm intrigued myself now... I'm going to find the VoL site and check
out the vehicles concerned. I remember seeing DMU's on a school trip
to Edale in the mid 70s in white with one rail blue band, was that
because of PTE-funded interior refurbs?

On 26 Feb, 15:28, Stephen Allcroft <stephenallcr...@lycos.co.uk>
wrote:
> On 25 Feb, 20:41, Charlie Hulme <i...@davenportstation.org.uk> wrote:
>
> > Brian Robertson wrote:
>
> > > My friend says that they indicated some re gearing of the DMUs to cope with
> > > the Buxton line.
> > The gearing could not be changed, AFAIK. All had the same epicyclic
> > gearbox. Whether they 'coped' with the Buxton line is a moot point.
> > Ascent of the climbs could be somewhat slow, espcially with
> > one or more of the 6 engines out of action ....
>
> The gearbox(es) themselves were a standard Self Changing Gears
> (Leyland Pneumocyclic) type of semi automatic, but AIUI the
> _final_drive_ gearing could be varied. Indeed CIE had AEC/SCG BUT
> DMUs(*) with two-speed final drives, so they would do around 40 mile/
> hour on suburban stopping trains and 70 mile/hour on expresses.
>
> (*)Sorry about all the TLAs.
>
> I'm intrigued myself now... I'm going to find the VoL site and check
> out the vehicles concerned. I remember seeing DMU's on a school trip
> to Edale in the mid 70s in white with one rail blue band, was that
> because of PTE-funded interior refurbs?

I remember when I worked for London Transport Signalling Department
travelling into London from Bedford in 2 x 4 car sets (some were
Leyland, others were Rolls Royce) but they could be driven in
multiple.

The rule used to be trailer coach in summer - it would be cool(er),
powered coach in winter - noisy but warm!

Cheers

Puffernutter