A very informative video on this innovative experimental locomotive of 1951.

https://www.youtube.com/watch?v=doBPp3ZfgLc

Codger <codger524@gmail.com> wrote:
> A very informative video on this innovative experimental locomotive of 1951.
>
> https://www.youtube.com/watch?v=doBPp3ZfgLc
>

I’m not sure I follow the logic of the design. At slow speeds, when you
need to start a train, there is only 1 of 4 engines in use.

The other thing that stood out was the use of milling machines without the
use of safety spectacles.

On 25/12/2023 10:47, Tweed wrote:
> Codger <codger524@gmail.com> wrote:
>> A very informative video on this innovative experimental locomotive of 1951.
>>
>> https://www.youtube.com/watch?v=doBPp3ZfgLc
>>
>
> I’m not sure I follow the logic of the design. At slow speeds, when you
> need to start a train, there is only 1 of 4 engines in use.
>
> The other thing that stood out was the use of milling machines without the
> use of safety spectacles.
>
I'm afraid that was the norm at that time.

Tweed <usenet.tweed@gmail.com> wrote:
> Codger <codger524@gmail.com> wrote:
>> A very informative video on this innovative experimental locomotive of 1951.
>>
>> https://www.youtube.com/watch?v=doBPp3ZfgLc
>>
>
> I’m not sure I follow the logic of the design. At slow speeds, when you
> need to start a train, there is only 1 of 4 engines in use.

There's more about the design in

https://en.wikipedia.org/wiki/British_Rail_10100

At low speed, locos are traction limited, not oower limited, so only having
one engine connected is not necessarily a bad thing, particularly as the
supercharged engines were designed to produce peak power at lower speeds.

My first though was that a lot of power was being transmitted through bevel
gears, whuch would probably have a short life. But it didn't stay in
service long enough to find out.

Recliner <recliner.usenet@gmail.com> wrote:
> Tweed <usenet.tweed@gmail.com> wrote:
>> Codger <codger524@gmail.com> wrote:
>>> A very informative video on this innovative experimental locomotive of 1951.
>>>
>>> https://www.youtube.com/watch?v=doBPp3ZfgLc
>>>
>>
>> I’m not sure I follow the logic of the design. At slow speeds, when you
>> need to start a train, there is only 1 of 4 engines in use.
>
> There's more about the design in
>
> https://en.wikipedia.org/wiki/British_Rail_10100
>
> At low speed, locos are traction limited, not oower limited, so only having
> one engine connected is not necessarily a bad thing, particularly as the
> supercharged engines were designed to produce peak power at lower speeds.
>
> My first though was that a lot of power was being transmitted through bevel
> gears, whuch would probably have a short life. But it didn't stay in
> service long enough to find out.
>
>

By traction limited do you mean limited by the friction between wheel and
rail?

On Mon, 25 Dec 2023 11:17:54 GMT
Recliner <recliner.usenet@gmail.com> wrote:
>Tweed <usenet.tweed@gmail.com> wrote:
>> Codger <codger524@gmail.com> wrote:
>>> A very informative video on this innovative experimental locomotive of
>1951.
>>>
>>> https://www.youtube.com/watch?v=doBPp3ZfgLc
>>>
>>
>> I’m not sure I follow the logic of the design. At slow speeds, when you
>> need to start a train, there is only 1 of 4 engines in use.
>
>There's more about the design in
>
>https://en.wikipedia.org/wiki/British_Rail_10100

Seems rather over complicated. What did they have against a standard torque
converter and gearbox?

Tweed <usenet.tweed@gmail.com> wrote:
> Recliner <recliner.usenet@gmail.com> wrote:
>> Tweed <usenet.tweed@gmail.com> wrote:
>>> Codger <codger524@gmail.com> wrote:
>>>> A very informative video on this innovative experimental locomotive of 1951.
>>>>
>>>> https://www.youtube.com/watch?v=doBPp3ZfgLc
>>>>
>>>
>>> I’m not sure I follow the logic of the design. At slow speeds, when you
>>> need to start a train, there is only 1 of 4 engines in use.
>>
>> There's more about the design in
>>
>> https://en.wikipedia.org/wiki/British_Rail_10100
>>
>> At low speed, locos are traction limited, not oower limited, so only having
>> one engine connected is not necessarily a bad thing, particularly as the
>> supercharged engines were designed to produce peak power at lower speeds.
>>
>> My first though was that a lot of power was being transmitted through bevel
>> gears, whuch would probably have a short life. But it didn't stay in
>> service long enough to find out.
>>
>>
>
> By traction limited do you mean limited by the friction between wheel and
> rail?

Yes. Steam locos need skilled drivers to stop the wheels spinning when
starting; modern trains have electronic WSP. In the absence of such tech,
reducing the power at the wheel during initial acceleration is a potential
substitute.

<Muttley@dastardlyhq.com> wrote:
> On Mon, 25 Dec 2023 11:17:54 GMT
> Recliner <recliner.usenet@gmail.com> wrote:
>> Tweed <usenet.tweed@gmail.com> wrote:
>>> Codger <codger524@gmail.com> wrote:
>>>> A very informative video on this innovative experimental locomotive of
>> 1951.
>>>>
>>>> https://www.youtube.com/watch?v=doBPp3ZfgLc
>>>>
>>>
>>> I’m not sure I follow the logic of the design. At slow speeds, when you
>>> need to start a train, there is only 1 of 4 engines in use.
>>
>> There's more about the design in
>>
>> https://en.wikipedia.org/wiki/British_Rail_10100
>
> Seems rather over complicated. What did they have against a standard torque
> converter and gearbox?

It was to avoid changing gear. Epicyclic gearboxes were a later solution to
the problem.

On Mon, 25 Dec 2023 16:12:20 GMT
Recliner <recliner.usenet@gmail.com> wrote:
><Muttley@dastardlyhq.com> wrote:
>> On Mon, 25 Dec 2023 11:17:54 GMT
>> Recliner <recliner.usenet@gmail.com> wrote:
>>> Tweed <usenet.tweed@gmail.com> wrote:
>>>> Codger <codger524@gmail.com> wrote:
>>>>> A very informative video on this innovative experimental locomotive of
>>> 1951.
>>>>>
>>>>> https://www.youtube.com/watch?v=doBPp3ZfgLc
>>>>>
>>>>
>>>> I’m not sure I follow the logic of the design. At slow speeds, when you
>>>> need to start a train, there is only 1 of 4 engines in use.
>>>
>>> There's more about the design in
>>>
>>> https://en.wikipedia.org/wiki/British_Rail_10100
>>
>> Seems rather over complicated. What did they have against a standard torque
>> converter and gearbox?
>
>It was to avoid changing gear. Epicyclic gearboxes were a later solution to
>the problem.

Must be a better way than that. Actually I guess there was since it wasn't
used again.

<Muttley@dastardlyhq.com> wrote:
> On Mon, 25 Dec 2023 16:12:20 GMT
> Recliner <recliner.usenet@gmail.com> wrote:
>> <Muttley@dastardlyhq.com> wrote:
>>> On Mon, 25 Dec 2023 11:17:54 GMT
>>> Recliner <recliner.usenet@gmail.com> wrote:
>>>> Tweed <usenet.tweed@gmail.com> wrote:
>>>>> Codger <codger524@gmail.com> wrote:
>>>>>> A very informative video on this innovative experimental locomotive of
>>>> 1951.
>>>>>>
>>>>>> https://www.youtube.com/watch?v=doBPp3ZfgLc
>>>>>>
>>>>>
>>>>> I’m not sure I follow the logic of the design. At slow speeds, when you
>>>>> need to start a train, there is only 1 of 4 engines in use.
>>>>
>>>> There's more about the design in
>>>>
>>>> https://en.wikipedia.org/wiki/British_Rail_10100
>>>
>>> Seems rather over complicated. What did they have against a standard torque
>>> converter and gearbox?
>>
>> It was to avoid changing gear. Epicyclic gearboxes were a later solution to
>> the problem.
>
> Must be a better way than that. Actually I guess there was since it wasn't
> used again.

Yes, like most countries, BR went diesel electric for its locos (apart from
some dabbling with diesel hydraulics in the western region), but early DMUs
were diesel mechanical, as were the final Derby DMUs (172s) and the new CAF
DMUs (197 etc.).

On Mon, 25 Dec 2023 21:26:03 GMT, Recliner <recliner.usenet@gmail.com>
wrote:

><Muttley@dastardlyhq.com> wrote:
>> On Mon, 25 Dec 2023 16:12:20 GMT
>> Recliner <recliner.usenet@gmail.com> wrote:
>>> <Muttley@dastardlyhq.com> wrote:
>>>> On Mon, 25 Dec 2023 11:17:54 GMT
>>>> Recliner <recliner.usenet@gmail.com> wrote:

>>>>> https://en.wikipedia.org/wiki/British_Rail_10100
>>>>
>>>> Seems rather over complicated. What did they have against a standard torque
>>>> converter and gearbox?
>>>
>>> It was to avoid changing gear. Epicyclic gearboxes were a later solution to
>>> the problem.
>>
>> Must be a better way than that. Actually I guess there was since it wasn't
>> used again.
>
>Yes, like most countries, BR went diesel electric for its locos (apart from
>some dabbling with diesel hydraulics in the western region), but early DMUs
>were diesel mechanical, as were the final Derby DMUs (172s) and the new CAF
>DMUs (197 etc.).

Yes; it was a bit of a dead end in development terms. But, for its time, it
was effective. It was lighter and more powerful than other early diesels,
and the concept, despite comments upthread, made engineering sense.

The reason it didn't succeed wasn't because it was a bad design per se, it's
because diesel-hydraulic in general lost out to diesel-electric in the long
run. Even if the Fell had become an entire class (like the Hymek), it would
still have been relatively short-lived. But, as a diesel-hydraulic, it was
actually one of the more successful early experiments.

The reason it didn't go into production was more to do with bad luck than
bad design. The failure of the gearbox due to a loose bolt (which was purely
a maintenance failing, not a design flaw) meant that by the time it was back
in testing, the momentum had already moved away from hydraulic transmission.
But maybe the biggest reason it never made it into production is because it
was originally designed for the LMS, and then operated by BR Midland Region.
Had it been operated by Western Region, which was more inclined to trial
hydraulics in the first place (eg, the aforementioned Hymek), it might have
had a much better chance of being a production design.

Mark

Mark Goodge <usenet@listmail.good-stuff.co.uk> wrote:
> On Mon, 25 Dec 2023 21:26:03 GMT, Recliner <recliner.usenet@gmail.com>
> wrote:
>
>> <Muttley@dastardlyhq.com> wrote:
>>> On Mon, 25 Dec 2023 16:12:20 GMT
>>> Recliner <recliner.usenet@gmail.com> wrote:
>>>> <Muttley@dastardlyhq.com> wrote:
>>>>> On Mon, 25 Dec 2023 11:17:54 GMT
>>>>> Recliner <recliner.usenet@gmail.com> wrote:
>
>>>>>> https://en.wikipedia.org/wiki/British_Rail_10100
>>>>>
>>>>> Seems rather over complicated. What did they have against a standard torque
>>>>> converter and gearbox?
>>>>
>>>> It was to avoid changing gear. Epicyclic gearboxes were a later solution to
>>>> the problem.
>>>
>>> Must be a better way than that. Actually I guess there was since it wasn't
>>> used again.
>>
>> Yes, like most countries, BR went diesel electric for its locos (apart from
>> some dabbling with diesel hydraulics in the western region), but early DMUs
>> were diesel mechanical, as were the final Derby DMUs (172s) and the new CAF
>> DMUs (197 etc.).
>
> Yes; it was a bit of a dead end in development terms. But, for its time, it
> was effective. It was lighter and more powerful than other early diesels,
> and the concept, despite comments upthread, made engineering sense.
>
> The reason it didn't succeed wasn't because it was a bad design per se, it's
> because diesel-hydraulic in general lost out to diesel-electric in the long
> run. Even if the Fell had become an entire class (like the Hymek), it would
> still have been relatively short-lived. But, as a diesel-hydraulic, it was
> actually one of the more successful early experiments.
>
> The reason it didn't go into production was more to do with bad luck than
> bad design. The failure of the gearbox due to a loose bolt (which was purely
> a maintenance failing, not a design flaw) meant that by the time it was back
> in testing, the momentum had already moved away from hydraulic transmission.
> But maybe the biggest reason it never made it into production is because it
> was originally designed for the LMS, and then operated by BR Midland Region.
> Had it been operated by Western Region, which was more inclined to trial
> hydraulics in the first place (eg, the aforementioned Hymek), it might have
> had a much better chance of being a production design.
>
> Mark
>

I’m unconvinced that six separate diesel engines is a sensible engineering
choice. It increases the probability of failure immensely.

On Wed, 27 Dec 2023 08:35:05 -0000 (UTC)
Tweed <usenet.tweed@gmail.com> wrote:
>Mark Goodge <usenet@listmail.good-stuff.co.uk> wrote:
>> and the concept, despite comments upthread, made engineering sense.
>>
>> The reason it didn't succeed wasn't because it was a bad design per se, it's
>> because diesel-hydraulic in general lost out to diesel-electric in the long
>> run. Even if the Fell had become an entire class (like the Hymek), it would
>> still have been relatively short-lived. But, as a diesel-hydraulic, it was
>> actually one of the more successful early experiments.
>>
>> The reason it didn't go into production was more to do with bad luck than
>> bad design. The failure of the gearbox due to a loose bolt (which was purely
>> a maintenance failing, not a design flaw) meant that by the time it was back
>> in testing, the momentum had already moved away from hydraulic transmission.
>> But maybe the biggest reason it never made it into production is because it
>> was originally designed for the LMS, and then operated by BR Midland Region.
>> Had it been operated by Western Region, which was more inclined to trial
>> hydraulics in the first place (eg, the aforementioned Hymek), it might have
>> had a much better chance of being a production design.
>>
>> Mark
>>
>
>I’m unconvinced that six separate diesel engines is a sensible engineering
>choice. It increases the probability of failure immensely.

Not to mentioning repeatedly filling and draining various fluid clutches with
all the pumps and valves required. Sounds like a maintenance nightmare and I
suspect long term reliability would have been in the toilet.

Tweed <usenet.tweed@gmail.com> wrote:
> Mark Goodge <usenet@listmail.good-stuff.co.uk> wrote:
>> On Mon, 25 Dec 2023 21:26:03 GMT, Recliner <recliner.usenet@gmail.com>
>> wrote:
>>
>>> <Muttley@dastardlyhq.com> wrote:
>>>> On Mon, 25 Dec 2023 16:12:20 GMT
>>>> Recliner <recliner.usenet@gmail.com> wrote:
>>>>> <Muttley@dastardlyhq.com> wrote:
>>>>>> On Mon, 25 Dec 2023 11:17:54 GMT
>>>>>> Recliner <recliner.usenet@gmail.com> wrote:
>>
>>>>>>> https://en.wikipedia.org/wiki/British_Rail_10100
>>>>>>
>>>>>> Seems rather over complicated. What did they have against a standard torque
>>>>>> converter and gearbox?
>>>>>
>>>>> It was to avoid changing gear. Epicyclic gearboxes were a later solution to
>>>>> the problem.
>>>>
>>>> Must be a better way than that. Actually I guess there was since it wasn't
>>>> used again.
>>>
>>> Yes, like most countries, BR went diesel electric for its locos (apart from
>>> some dabbling with diesel hydraulics in the western region), but early DMUs
>>> were diesel mechanical, as were the final Derby DMUs (172s) and the new CAF
>>> DMUs (197 etc.).
>>
>> Yes; it was a bit of a dead end in development terms. But, for its time, it
>> was effective. It was lighter and more powerful than other early diesels,
>> and the concept, despite comments upthread, made engineering sense.
>>
>> The reason it didn't succeed wasn't because it was a bad design per se, it's
>> because diesel-hydraulic in general lost out to diesel-electric in the long
>> run. Even if the Fell had become an entire class (like the Hymek), it would
>> still have been relatively short-lived. But, as a diesel-hydraulic, it was
>> actually one of the more successful early experiments.
>>
>> The reason it didn't go into production was more to do with bad luck than
>> bad design. The failure of the gearbox due to a loose bolt (which was purely
>> a maintenance failing, not a design flaw) meant that by the time it was back
>> in testing, the momentum had already moved away from hydraulic transmission.
>> But maybe the biggest reason it never made it into production is because it
>> was originally designed for the LMS, and then operated by BR Midland Region.
>> Had it been operated by Western Region, which was more inclined to trial
>> hydraulics in the first place (eg, the aforementioned Hymek), it might have
>> had a much better chance of being a production design.
>>
>> Mark
>>
>
> I’m unconvinced that six separate diesel engines is a sensible engineering
> choice. It increases the probability of failure immensely.
>
>

On the other hand if it could run (at reduced maximum speed) with one or
more engine shut down (like a DMU, Western, Deltic, HST etc.), then perhaps
that reduces the chances of an engine failure blocking the line…

Anna Noyd-Dryver

Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
> Tweed <usenet.tweed@gmail.com> wrote:
>> Mark Goodge <usenet@listmail.good-stuff.co.uk> wrote:
>>> On Mon, 25 Dec 2023 21:26:03 GMT, Recliner <recliner.usenet@gmail.com>
>>> wrote:
>>>
>>>> <Muttley@dastardlyhq.com> wrote:
>>>>> On Mon, 25 Dec 2023 16:12:20 GMT
>>>>> Recliner <recliner.usenet@gmail.com> wrote:
>>>>>> <Muttley@dastardlyhq.com> wrote:
>>>>>>> On Mon, 25 Dec 2023 11:17:54 GMT
>>>>>>> Recliner <recliner.usenet@gmail.com> wrote:
>>>
>>>>>>>> https://en.wikipedia.org/wiki/British_Rail_10100
>>>>>>>
>>>>>>> Seems rather over complicated. What did they have against a standard torque
>>>>>>> converter and gearbox?
>>>>>>
>>>>>> It was to avoid changing gear. Epicyclic gearboxes were a later solution to
>>>>>> the problem.
>>>>>
>>>>> Must be a better way than that. Actually I guess there was since it wasn't
>>>>> used again.
>>>>
>>>> Yes, like most countries, BR went diesel electric for its locos (apart from
>>>> some dabbling with diesel hydraulics in the western region), but early DMUs
>>>> were diesel mechanical, as were the final Derby DMUs (172s) and the new CAF
>>>> DMUs (197 etc.).
>>>
>>> Yes; it was a bit of a dead end in development terms. But, for its time, it
>>> was effective. It was lighter and more powerful than other early diesels,
>>> and the concept, despite comments upthread, made engineering sense.
>>>
>>> The reason it didn't succeed wasn't because it was a bad design per se, it's
>>> because diesel-hydraulic in general lost out to diesel-electric in the long
>>> run. Even if the Fell had become an entire class (like the Hymek), it would
>>> still have been relatively short-lived. But, as a diesel-hydraulic, it was
>>> actually one of the more successful early experiments.
>>>
>>> The reason it didn't go into production was more to do with bad luck than
>>> bad design. The failure of the gearbox due to a loose bolt (which was purely
>>> a maintenance failing, not a design flaw) meant that by the time it was back
>>> in testing, the momentum had already moved away from hydraulic transmission.
>>> But maybe the biggest reason it never made it into production is because it
>>> was originally designed for the LMS, and then operated by BR Midland Region.
>>> Had it been operated by Western Region, which was more inclined to trial
>>> hydraulics in the first place (eg, the aforementioned Hymek), it might have
>>> had a much better chance of being a production design.
>>>
>>> Mark
>>>
>>
>> I’m unconvinced that six separate diesel engines is a sensible engineering
>> choice. It increases the probability of failure immensely.
>>
>>
>
> On the other hand if it could run (at reduced maximum speed) with one or
> more engine shut down (like a DMU, Western, Deltic, HST etc.), then perhaps
> that reduces the chances of an engine failure blocking the line…
>
>
> Anna Noyd-Dryver
>
>

But increases the probability of imposing delays on the line because it is
more often than not operating in a degraded mode because of an engine
failure.

I’m still trying to understand the assertion in the film that this entirely
mechanical system was more efficient than diesel electric.

Tweed <usenet.tweed@gmail.com> wrote:
> But increases the probability of imposing delays on the line because it is
> more often than not operating in a degraded mode because of an engine
> failure.
>
> I’m still trying to understand the assertion in the film that this entirely
> mechanical system was more efficient than diesel electric.

What were the electric traction options of the day? DC traction motors with
mercury arc rectifiers? I could imagine efficiency wasn't so great for
those.

On 27/12/2023 10:02, Tweed wrote:
> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>> Tweed <usenet.tweed@gmail.com> wrote:
>>> Mark Goodge <usenet@listmail.good-stuff.co.uk> wrote:
>>>> On Mon, 25 Dec 2023 21:26:03 GMT, Recliner <recliner.usenet@gmail.com>
>>>> wrote:
>>>>
>>>>> <Muttley@dastardlyhq.com> wrote:
>>>>>> On Mon, 25 Dec 2023 16:12:20 GMT
>>>>>> Recliner <recliner.usenet@gmail.com> wrote:
>>>>>>> <Muttley@dastardlyhq.com> wrote:
>>>>>>>> On Mon, 25 Dec 2023 11:17:54 GMT
>>>>>>>> Recliner <recliner.usenet@gmail.com> wrote:
>>>>
>>>>>>>>> https://en.wikipedia.org/wiki/British_Rail_10100
>>>>>>>>
>>>>>>>> Seems rather over complicated. What did they have against a standard torque
>>>>>>>> converter and gearbox?
>>>>>>>
>>>>>>> It was to avoid changing gear. Epicyclic gearboxes were a later solution to
>>>>>>> the problem.
>>>>>>
>>>>>> Must be a better way than that. Actually I guess there was since it wasn't
>>>>>> used again.
>>>>>
>>>>> Yes, like most countries, BR went diesel electric for its locos (apart from
>>>>> some dabbling with diesel hydraulics in the western region), but early DMUs
>>>>> were diesel mechanical, as were the final Derby DMUs (172s) and the new CAF
>>>>> DMUs (197 etc.).
>>>>
>>>> Yes; it was a bit of a dead end in development terms. But, for its time, it
>>>> was effective. It was lighter and more powerful than other early diesels,
>>>> and the concept, despite comments upthread, made engineering sense.
>>>>
>>>> The reason it didn't succeed wasn't because it was a bad design per se, it's
>>>> because diesel-hydraulic in general lost out to diesel-electric in the long
>>>> run. Even if the Fell had become an entire class (like the Hymek), it would
>>>> still have been relatively short-lived. But, as a diesel-hydraulic, it was
>>>> actually one of the more successful early experiments.
>>>>
>>>> The reason it didn't go into production was more to do with bad luck than
>>>> bad design. The failure of the gearbox due to a loose bolt (which was purely
>>>> a maintenance failing, not a design flaw) meant that by the time it was back
>>>> in testing, the momentum had already moved away from hydraulic transmission.
>>>> But maybe the biggest reason it never made it into production is because it
>>>> was originally designed for the LMS, and then operated by BR Midland Region.
>>>> Had it been operated by Western Region, which was more inclined to trial
>>>> hydraulics in the first place (eg, the aforementioned Hymek), it might have
>>>> had a much better chance of being a production design.
>>>
>>> I’m unconvinced that six separate diesel engines is a sensible engineering
>>> choice. It increases the probability of failure immensely.
>>
>> On the other hand if it could run (at reduced maximum speed) with one or
>> more engine shut down (like a DMU, Western, Deltic, HST etc.), then perhaps
>> that reduces the chances of an engine failure blocking the line…
>
> But increases the probability of imposing delays on the line because it is
> more often than not operating in a degraded mode because of an engine
> failure.
>
> I’m still trying to understand the assertion in the film that this entirely
> mechanical system was more efficient than diesel electric.

With six engines, it should be possible to run to timetable on five of
them on all but the most challenging of hills and grand prix starts.

Certes <Certes@example.org> wrote:
> On 27/12/2023 10:02, Tweed wrote:
>> Anna Noyd-Dryver <anna@noyd-dryver.com> wrote:
>>> Tweed <usenet.tweed@gmail.com> wrote:
>>>> Mark Goodge <usenet@listmail.good-stuff.co.uk> wrote:
>>>>> On Mon, 25 Dec 2023 21:26:03 GMT, Recliner <recliner.usenet@gmail.com>
>>>>> wrote:
>>>>>
>>>>>> <Muttley@dastardlyhq.com> wrote:
>>>>>>> On Mon, 25 Dec 2023 16:12:20 GMT
>>>>>>> Recliner <recliner.usenet@gmail.com> wrote:
>>>>>>>> <Muttley@dastardlyhq.com> wrote:
>>>>>>>>> On Mon, 25 Dec 2023 11:17:54 GMT
>>>>>>>>> Recliner <recliner.usenet@gmail.com> wrote:
>>>>>
>>>>>>>>>> https://en.wikipedia.org/wiki/British_Rail_10100
>>>>>>>>>
>>>>>>>>> Seems rather over complicated. What did they have against a standard torque
>>>>>>>>> converter and gearbox?
>>>>>>>>
>>>>>>>> It was to avoid changing gear. Epicyclic gearboxes were a later solution to
>>>>>>>> the problem.
>>>>>>>
>>>>>>> Must be a better way than that. Actually I guess there was since it wasn't
>>>>>>> used again.
>>>>>>
>>>>>> Yes, like most countries, BR went diesel electric for its locos (apart from
>>>>>> some dabbling with diesel hydraulics in the western region), but early DMUs
>>>>>> were diesel mechanical, as were the final Derby DMUs (172s) and the new CAF
>>>>>> DMUs (197 etc.).
>>>>>
>>>>> Yes; it was a bit of a dead end in development terms. But, for its time, it
>>>>> was effective. It was lighter and more powerful than other early diesels,
>>>>> and the concept, despite comments upthread, made engineering sense.
>>>>>
>>>>> The reason it didn't succeed wasn't because it was a bad design per se, it's
>>>>> because diesel-hydraulic in general lost out to diesel-electric in the long
>>>>> run. Even if the Fell had become an entire class (like the Hymek), it would
>>>>> still have been relatively short-lived. But, as a diesel-hydraulic, it was
>>>>> actually one of the more successful early experiments.
>>>>>
>>>>> The reason it didn't go into production was more to do with bad luck than
>>>>> bad design. The failure of the gearbox due to a loose bolt (which was purely
>>>>> a maintenance failing, not a design flaw) meant that by the time it was back
>>>>> in testing, the momentum had already moved away from hydraulic transmission.
>>>>> But maybe the biggest reason it never made it into production is because it
>>>>> was originally designed for the LMS, and then operated by BR Midland Region.
>>>>> Had it been operated by Western Region, which was more inclined to trial
>>>>> hydraulics in the first place (eg, the aforementioned Hymek), it might have
>>>>> had a much better chance of being a production design.
>>>>
>>>> I’m unconvinced that six separate diesel engines is a sensible engineering
>>>> choice. It increases the probability of failure immensely.
>>>
>>> On the other hand if it could run (at reduced maximum speed) with one or
>>> more engine shut down (like a DMU, Western, Deltic, HST etc.), then perhaps
>>> that reduces the chances of an engine failure blocking the line…
>>
>> But increases the probability of imposing delays on the line because it is
>> more often than not operating in a degraded mode because of an engine
>> failure.
>>
>> I’m still trying to understand the assertion in the film that this entirely
>> mechanical system was more efficient than diesel electric.
>
> With six engines, it should be possible to run to timetable on five of
> them on all but the most challenging of hills and grand prix starts.
>

But it was utterly dependent on the two smaller ones to power air blowers.
So the failure modes are more complex.

Theo <theom+news@chiark.greenend.org.uk> wrote:
> Tweed <usenet.tweed@gmail.com> wrote:
>> But increases the probability of imposing delays on the line because it is
>> more often than not operating in a degraded mode because of an engine
>> failure.
>>
>> I’m still trying to understand the assertion in the film that this entirely
>> mechanical system was more efficient than diesel electric.
>
> What were the electric traction options of the day? DC traction motors with
> mercury arc rectifiers? I could imagine efficiency wasn't so great for
> those.
>

You don’t need a rectifier if you have an onboard generator.

On Wed, 27 Dec 2023 08:35:05 -0000 (UTC), Tweed <usenet.tweed@gmail.com>
wrote:

>Mark Goodge <usenet@listmail.good-stuff.co.uk> wrote:
>>
>> The reason it didn't go into production was more to do with bad luck than
>> bad design. The failure of the gearbox due to a loose bolt (which was purely
>> a maintenance failing, not a design flaw) meant that by the time it was back
>> in testing, the momentum had already moved away from hydraulic transmission.
>> But maybe the biggest reason it never made it into production is because it
>> was originally designed for the LMS, and then operated by BR Midland Region.
>> Had it been operated by Western Region, which was more inclined to trial
>> hydraulics in the first place (eg, the aforementioned Hymek), it might have
>> had a much better chance of being a production design.
>
>I’m unconvinced that six separate diesel engines is a sensible engineering
>choice. It increases the probability of failure immensely.

But it also increases redundancy if one does. Rather than being terminal, a
single engine failure would still allow the loco to limp home.

Of course, we have no idea how effective the Fell system would have been in
production, because it never made it that far. But it wasn't as wacky a
design as some people make out. It was a genuine, well-thought-out
experiment aimed at addressing some of the known weaknesses of hydraulic
transmission. The problem wasn't that the Fell was a daft idea. It was
simply that it was attempting to solve the problem from the wrong end. In
the long run, the solution to the weaknesses in hydraulic transmission
wasn't found in better and more advanced hydraulic transmission systems, it
was found by abandoning them all in favour of electric transmission.

Mark

Mark Goodge <usenet@listmail.good-stuff.co.uk> wrote:
> On Wed, 27 Dec 2023 08:35:05 -0000 (UTC), Tweed <usenet.tweed@gmail.com>
> wrote:
>
>> Mark Goodge <usenet@listmail.good-stuff.co.uk> wrote:
>>>
>>> The reason it didn't go into production was more to do with bad luck than
>>> bad design. The failure of the gearbox due to a loose bolt (which was purely
>>> a maintenance failing, not a design flaw) meant that by the time it was back
>>> in testing, the momentum had already moved away from hydraulic transmission.
>>> But maybe the biggest reason it never made it into production is because it
>>> was originally designed for the LMS, and then operated by BR Midland Region.
>>> Had it been operated by Western Region, which was more inclined to trial
>>> hydraulics in the first place (eg, the aforementioned Hymek), it might have
>>> had a much better chance of being a production design.
>>
>> I’m unconvinced that six separate diesel engines is a sensible engineering
>> choice. It increases the probability of failure immensely.
>
> But it also increases redundancy if one does. Rather than being terminal, a
> single engine failure would still allow the loco to limp home.
>
> Of course, we have no idea how effective the Fell system would have been in
> production, because it never made it that far. But it wasn't as wacky a
> design as some people make out. It was a genuine, well-thought-out
> experiment aimed at addressing some of the known weaknesses of hydraulic
> transmission. The problem wasn't that the Fell was a daft idea. It was
> simply that it was attempting to solve the problem from the wrong end. In
> the long run, the solution to the weaknesses in hydraulic transmission
> wasn't found in better and more advanced hydraulic transmission systems, it
> was found by abandoning them all in favour of electric transmission.
>
> Mark
>

Except in the Shell film it was being sold as being more efficient than
Diesel electric. If I remember the film correctly no mention was made of
hydraulic transmission.

Tweed <usenet.tweed@gmail.com> wrote:
> Mark Goodge <usenet@listmail.good-stuff.co.uk> wrote:
> > Of course, we have no idea how effective the Fell system would have been in
> > production, because it never made it that far. But it wasn't as wacky a
> > design as some people make out. It was a genuine, well-thought-out
> > experiment aimed at addressing some of the known weaknesses of hydraulic
> > transmission. The problem wasn't that the Fell was a daft idea. It was
> > simply that it was attempting to solve the problem from the wrong end. In
> > the long run, the solution to the weaknesses in hydraulic transmission
> > wasn't found in better and more advanced hydraulic transmission systems, it
> > was found by abandoning them all in favour of electric transmission.
>
> Except in the Shell film it was being sold as being more efficient than
> Diesel electric. If I remember the film correctly no mention was made of
> hydraulic transmission.

I think the moral of the story was that progress was made faster in
electronics than in mechanics or hydraulics. We are after all talking
almost pre-transistor here (certainly pre power transistor). While 1940s
electrical technology may have been inefficient, rapid progress in
electronics (eg power rectifiers from 1950s) would have outpaced any
improvements in mechanical engineering. So the loco was solving a 1940s
problem not a 1950s problem.

Theo

In message <umh6ot$3u0kf$1@dont-email.me>, Tweed
<usenet.tweed@gmail.com> writes
>Except in the Shell film it was being sold as being more efficient than
>Diesel electric. If I remember the film correctly no mention was made of
>hydraulic transmission.
>

Wasn't it a hydraulic coupling between the engine and the gearbox, a
sort of combined clutch and brake (depending on whether that engine was
driving or not) ?

Adrian
--
To Reply :
replace "bulleid" with "adrian" - all mail to bulleid is rejected
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Every time someone says "I don't believe in trolls", another one dies.

Adrian <bulleid@ku.gro.lioff> wrote:
> In message <umh6ot$3u0kf$1@dont-email.me>, Tweed
> <usenet.tweed@gmail.com> writes
>> Except in the Shell film it was being sold as being more efficient than
>> Diesel electric. If I remember the film correctly no mention was made of
>> hydraulic transmission.
>>
>
> Wasn't it a hydraulic coupling between the engine and the gearbox, a
> sort of combined clutch and brake (depending on whether that engine was
> driving or not) ?
>
> Adrian

Well yes, but not a hydraulic transmission in the conventional sense.

On Wed, 27 Dec 2023 12:53:49 -0000 (UTC), Tweed <usenet.tweed@gmail.com>
wrote:

>Mark Goodge <usenet@listmail.good-stuff.co.uk> wrote:

>> Of course, we have no idea how effective the Fell system would have been in
>> production, because it never made it that far. But it wasn't as wacky a
>> design as some people make out. It was a genuine, well-thought-out
>> experiment aimed at addressing some of the known weaknesses of hydraulic
>> transmission. The problem wasn't that the Fell was a daft idea. It was
>> simply that it was attempting to solve the problem from the wrong end. In
>> the long run, the solution to the weaknesses in hydraulic transmission
>> wasn't found in better and more advanced hydraulic transmission systems, it
>> was found by abandoning them all in favour of electric transmission.
>
>Except in the Shell film it was being sold as being more efficient than
>Diesel electric. If I remember the film correctly no mention was made of
>hydraulic transmission.

At the time, hydraulic transmission was generally more efficient than
electric. The basic trade-off was that hydraulic was more efficient but less
flexible, while electric was more flexible but less efficient. The Fell was
an attempt to improve the flexibility of hydraulic while retaining - and
even increasing - its efficiency advantage. Prom a purely prototype
perspective, it was successful in that. It was more powerful, and cheaper to
run, than its nearest equivalent locos. But the downside of the Fell was
increased complexity, which, had it gone into production, may well have been
a significant issue. And in the long run, improvements in the efficiency of
electric transmission meant that the advantages of hydraulic transmission
were effectively negated. So the Fell was part of an evolutionary dead end;
even if it had gone into successful production it would probably have been a
short-lived class.

Mark