Hornby Merchant Navy announced (formerly Facebook leak)

[olivegreen]

The unkind have been known to say that the reason for the elaborate nameplates on the MN, WC and BB classes was to increase weight over the driving wheels.

 

Not that I would subscribe to such a view, of course… !

[Hroth]

Nah, this is real slipping..........

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

Other slips are available.......

N. Gresley.

Given the right conditions, any loco can be persuaded to slip.  Even GWR Kings, though the GWR mainly slipped coaches!

 

But Bulleid pacifics (both MN and WC/BoB) were masters of the slip. In the sense that they were very prone to doing so.....

 

(Don't take my word for it, have a look at 21C 6 in London Terminus,  post #626 above, at 13:55 onwards!)

Edited August 29, 2016 by Hroth

[railroadbill]

There is a very good clip of 21C 6 in this video on You Tube ............ full air smoothed, no side smoke deflectors. Appears at 13 mins 52 seconds, the whole video is worth a watch if you have a few spare minutes.

 

 https://www.youtube.com/watch?v=ZYhsx9uDBJQ

Really interesting, thanks for finding that. A lot of historical detail, such as the large number of women working on the railway in wartime and barrage balloons in the distance behind the track workers.  (Testing the track circuits using a row of light bulbs was interesting).

 

According to the RCTS book on Bulleid pacifics, after late 1943 MNs worked 4 expresses out of Waterloo each day,  the 10.50 being  the equivalent of the ACE and loading up to 17 or 18 coaches.  The film shows Atlantic Coast Express boards on one carriage - just wondered if that was put on for the film, would they have normally bothered in wartime? Another point was the restaurant car service, not sure that would have been run in wartime? Thought they would have needed the maximum amount of accommodation, considering the vast amount of service personal the Southern must have carried, serving so many army and navy bases. (As the film shows).

 

Seeing an engine the size of an MN compared to other southern locos must have been a bit of a morale booster.   In 1944 21C6 was a Salisbury engine together with 7-10. It ran 100140 miles to first general repair with 74 days in works.  Apparently unusual to have more than 2 of the 4 in traffic at any one time at that point.

 

Fascinating to see an MN in early condition slipping its way out of Waterloo, though.  Smokebox door seemed to have some burns on it to the left. (And without the extra handrail that was fitted to the door on later engines).

 

Also spotted a Schools and an M7.

 

Finally a great structure to the film with  the couple on a date going into the news theatre to see the film that they were actually in!

[Mallard60022]

Given the right conditions, any loco can be persuaded to slip.  Even GWR Kings, though the GWR mainly slipped coaches!

 

But Bulleid pacifics (both MN and WC/BoB) were masters of the slip. In the sense that they were very prone to doing so.....

 

(Don't take my word for it, have a look at 21C 6 in London Terminus,  post #626 above, at 13:55 onwards!)

Really, 21C6 hardly slipped at all compared to most Bulleid starts from Waterloo.

One of the reasons they slipped quite easily was that they were quite light in weight, in comparison to the big beasts of the LMS and LNER. They were somewhat better as modified as the weight distribution was different and about 4 tons heavier.. The 'originals' were even termed light Pacifics (well the B of B and W C ones anyway). 

4.6.0s are almost always more sure footed than Pacifics; someone explained why once but it was too complicated for me. 

O.V. Bulleid

Edited August 29, 2016 by Mallard60022

[MikeParkin65]

There is a very good clip of 21C 6 in this video on You Tube ............ full air smoothed, no side smoke deflectors. Appears at 13 mins 52 seconds, the whole video is worth a watch if you have a few spare minutes.

 

 https://www.youtube.com/watch?v=ZYhsx9uDBJQ

Magnificent!

[melmerby]

 

One of the reasons they slipped quite easily was that they were quite light in weight, in comparison to the big beasts of the LMS and LNER. They were somewhat better as modified as the weight distribution was different and about 4 tons heavier.. The 'originals' were even termed light Pacifics (well the B of B and W C ones anyway). 

4.6.0s are almost always more sure footed than Pacifics; someone explained why once but it was too complicated for me. 

O.V. Bulleid

An interesting comparison of before and after is the Coronations which lost about 3 tons when the casing was removed but the MNs gained between 3 and 4 tons.

No doubt a fair bit of the extra came from three full sets of Walschaerts gear compared to not a lot before!

I believe the Box-Pok wheels had to have some extra weight to balance them as well.

Even in rebuilt form they were still light over the drivers compared to other large Pacifics and the Kings.

 

I still fancy one of the "original" condition ones to go with the also "not in my period/area" P2!

 

Keith

 

BTW I assume a 4-6-0 is more sure footed as when a loco starts the weight distribution shifts backwards and on a 4-6-0 more will be over the rear driver. On a Pacific it will be over the trailing truck. Maybe someone could verify this point.

Edited August 29, 2016 by melmerby

[Cor-onGRT4]

Magnificent!

How about this one, construction of the MN and naming of Channel Packet,in 1941

hope the link will work, my first time i do this

 

https//www.youtube.com/watch?voj_mmDGIZHO0

[Cor-onGRT4]

There is a very good clip of 21C 6 in this video on You Tube ............ full air smoothed, no side smoke deflectors. Appears at 13 mins 52 seconds, the whole video is worth a watch if you have a few spare minutes.

 

 https://www.youtube.com/watch?v=ZYhsx9uDBJQ

How about this one, the construction of the MN and naming of Channel Packet in 1941

Hope the link will work, first time for me.

 

Southern steam- the early days of the Bulleid Pacifics

 

https//www.youtube.comwatch?voj_mmDGIZHO0

Edited August 29, 2016 by Cor-onGRT4

[Cor-onGRT4]

How about this one, construction of the MN and naming of Channel Packet,in 1941

hope the link will work, my first time i do this

 

https//www.youtube.com/watch?voj_mmDGIZHO0

Sorry, not good, forgot some, hope this will work

 

https://www.youtube.com/watch?v=j_mmDGIZHO0

[Cor-onGRT4]

How about this one, construction of the MN and naming of Channel Packet,in 1941

hope the link will work, my first time i do this

 

https//www.youtube.com/watch?voj_mmDGIZHO0

Sorry type fault, hope this will work

 

Southern steam - the early days of the Bulleid Pacifics

 

https://www.youtube.com/watch?v=j_mmDGIZHO0

[Budgie]

On a Pacific it will be over the trailing truck. Maybe someone could verify this point.

In that case why didn't Bulleid use a booster on the trailing truck, as many American loco designers did?

[Ozexpatriate]

How about this one, construction of the MN and naming of Channel Packet,in 1941

hope the link will work, my first time i do this

If you are using a PC, click on the link in your browser (to select it) and hit 'control C' (to copy). Then editing a post, click 'control v' to paste. The whole link will then appear in your post.

 

The link you are posting appears to be missing a colon, or you have substituted a capital I (i) for a lower case l (ell).

 

Is this the film?

 

https://www.youtube.com/watch?v=j_mmDGlZHO0

Edited August 30, 2016 by Ozexpatriate

[Dunsignalling]

In that case why didn't Bulleid use a booster on the trailing truck, as many American loco designers did?

The Merchant Navies were already at the maximum weight the SR Civil Engineer would accept; in fact, 21C1 and 21C2 exceeded it when first built.

 

Bulleid previously worked as Gresley's assistant on the LNER, the only UK railway (IIRC) to try boosters so would have known about their advantages and disadvantages. 

 

What worked on 180-ton locos in the USA wouldn't necessarily transfer to ones half that size over here, and the LNER didn't persist with boosters for long.

 

John

[Cor-onGRT4]

If you are using a PC, click on the link in your browser (to select it) and hit 'control C' (to copy). Then editing a post, click 'control v' to paste. The whole link will then appear in your post.

 

The link you are posting appears to be missing a colon, or you have substituted a capital I (i) for a lower case l (ell).

 

Is this the film?

 

https://www.youtube.com/watch?v=j_mmDGlZHO0

Thanks for posting , that's the one i try to post but not succeeded, hope you all like it.

And thanks for explaning how it works, will help me next time, was indeed a small instead of a capital

[melmerby]

Did anyone else notice that although the boiler pressure gauge was red-lined at 280psi it was only at 250psi prior to departure with it's train.

 

Keith

[Hroth]

Did anyone else notice that although the boiler pressure gauge was red-lined at 280psi it was only at 250psi prior to departure with it's train.

 

Keith

Not knowing that much about boiler safety margins as indicated on locomotive steam pressure gauges, what pressure the safety valves were/are actually set to and how difficult it is to maintain a particular pressure, I'd hazard a guess that blowing off steam while in the station (expecially a terminus) was frowned upon and so the fireman maintained the steam pressure at a good working value for starting purposes and that a build up to full pressure would be relatively easy to achieve.

 

Of course, if the terminus/station has an immediate incline upon starting, then the margin between keeping the engine quiet and having enough power for a vicious bit of climbing might be a bit tight!

 

(waves hands about in a convincing manner)

Edited August 30, 2016 by Hroth

[toboldlygo]

Did anyone else notice that although the boiler pressure gauge was red-lined at 280psi it was only at 250psi prior to departure with it's train.

 

Keith

The boiler pressure was 280 psi when the class was introduced - one of the highest pressures of a boiler on British Rails*. It was later reduced to 250 psi, hence the gauge redlining at 280.

 

*County class boiler pressure was the only class that had a higher pressure than the MN.

[34theletterbetweenB&D]

...Bulleid previously worked as Gresley's assistant on the LNER, the only UK railway (IIRC) to try boosters so would have known about their advantages and disadvantages. 

 

What worked on 180-ton locos in the USA wouldn't necessarily transfer to ones half that size over here, and the LNER didn't persist with boosters for long...

And for that matter, neither did North American designers. Better to design for sufficient power from the regular engines on the locomotive, rather than drag around auxiliary engines which were dead weight most of the time, and increased both first and maintenance cost.

[JSpencer]

Not knowing that much about boiler safety margins as indicated on locomotive steam pressure gauges, what pressure the safety valves were/are actually set to and how difficult it is to maintain a particular pressure, I'd hazard a guess that blowing off steam while in the station (expecially a terminus) was frowned upon and so the fireman maintained the steam pressure at a good working value for starting purposes and that a build up to full pressure would be relatively easy to achieve.

 

Of course, if the terminus/station has an immediate incline upon starting, then the margin between keeping the engine quiet and having enough power for a vicious bit of climbing might be a bit tight!

 

(waves hands about in a convincing manner)

 

The safety valves would go off at 280 LBs per square inch. 280 was the safety limit. Tractive effort figures always used 80% of that. Firemen would normally build up steam while the loco was stopped and get close to that limit.

 

Once underway, it was harder to build up steam simply because the loco would be using it, especially going up hill.  While diesel locos could be started and warmed up fairly quickly, and you can accelerate rate them to generate more power as required, steam locos need to build up power in reserve first.

So a driver leaving the station should always find himself with a loco pretty much with a full reserve of power and a loco almost at max power (unless the train was light). A fireman providing him with an engine not near the max would probably get a good talking too, because the chances to build up a head of steam underway will represent some challenges, especially a big heavy train that needs to move at speed.

 

Jarvis figured the Bulleids did not need to work at 280Lbs as they could cope with traffic using less power. Reducing the pressure to 250 allows economies in both coal and maintenance. In some respect, Bulleid produced his design to work with wartime loads, Jarvis adopted them for peace time so both were right to use the boiler pressures they choose in hindsight really. Which in hindsight also means that the Bulleid was flexible to both peace and wartime. The Gresley's pacific s suffered in wartime, the Thomson/Peppercorns pacific s were not economical in peacetime.

[JSpencer]

And for that matter, neither did North American designers. Better to design for sufficient power from the regular engines on the locomotive, rather than drag around auxiliary engines which were dead weight most of the time, and increased both first and maintenance cost.

 

In my opinion, Bulleid's leader was the ultimate expression of having too many auxiliary engines. Remember that was a giant design intended to replace an M7. In many trials, only one power bogie was actually at work.

[sandra]

I didn't think 21C6 slipped too much at all, not as much as is sometimes suggested. I have been told that locomotives were not allowed to use sanding gear when leaving Waterloo as all the platforms had the third rail and there was a danger of sand building up and possibly providing a route to earth, particularly when wet. This may explain the reports of excessive slipping when leaving Waterloo.

 

However what interested me was the suggestion in the film that an electric unit could be leaving the station only four minutes after arriving. I wonder if that was really the case for certainly today it seems to take much longer even with sliding doors. I also noted that the film seemed to show a train moving out of the platform with doors still open and a female member of staff closing them as it passed. That seems very unlikely and I wonder how much of what was shown was just for the film cameras.

 

Sandra

[melmerby]

The boiler pressure was 280 psi when the class was introduced - one of the highest pressures of a boiler on British Rails*. It was later reduced to 250 psi, hence the gauge redlining at 280.

 

*County class boiler pressure was the only class that had a higher pressure than the MN.

But it was 280psi when the film was made so the boiler/loco was down on power at departure.

 

Normally a fireman would hope to get the pressure just below valve valve lift so as to have maximum power available without wasting steam or energy by blowing off.

Many a time I have seen, during BR days, a loco held before departure for some reason and the the valves lift.

The fireman had skilfully made the fire so that maximum power would be available when the driver required it but the delay meant the steam wasn't being used.

 

Keith

[The Stationmaster]

I didn't think 21C6 slipped too much at all, not as much as is sometimes suggested. I have been told that locomotives were not allowed to use sanding gear when leaving Waterloo as all the platforms had the third rail and there was a danger of sand building up and possibly providing a route to earth, particularly when wet. This may explain the reports of excessive slipping when leaving Waterloo.

 

However what interested me was the suggestion in the film that an electric unit could be leaving the station only four minutes after arriving. I wonder if that was really the case for certainly today it seems to take much longer even with sliding doors. I also noted that the film seemed to show a train moving out of the platform with doors still open and a female member of staff closing them as it passed. That seems very unlikely and I wonder how much of what was shown was just for the film cameras.

 

Sandra

 

Four minutes sounds about right for a unit turning round - the biggest consumer of time would be the Driver getting from one end to the other but if the Drivers were changed over it could be done more rapidly and opening up/closing down a cab back then was far simpler than it is today.

 

I presume the lady Porter closing the doors was standard procedure - the passengers often didn't bother to close slamdoors and doing it that way would be quicker than walking the length of the train.  All a very different railway back then and the Southern didn't mess about when it came to running commuter services so anything which saved time and released a platform for the next train would be grabbed and exploited to the hilt.

[RFS]

I didn't think 21C6 slipped too much at all, not as much as is sometimes suggested. I have been told that locomotives were not allowed to use sanding gear when leaving Waterloo as all the platforms had the third rail and there was a danger of sand building up and possibly providing a route to earth, particularly when wet. This may explain the reports of excessive slipping when leaving Waterloo.

 

Sandra

 

I thought the reason for the ban on sanding at Waterloo was to prevent the build-up of sand interfering with the track circuiting system.

[JSpencer]

Four minutes sounds about right for a unit turning round - the biggest consumer of time would be the Driver getting from one end to the other but if the Drivers were changed over it could be done more rapidly and opening up/closing down a cab back then was far simpler than it is today.

 

I presume the lady Porter closing the doors was standard procedure - the passengers often didn't bother to close slamdoors and doing it that way would be quicker than walking the length of the train.  All a very different railway back then and the Southern didn't mess about when it came to running commuter services so anything which saved time and released a platform for the next train would be grabbed and exploited to the hilt.

I was impressed when I sax 4 minutes to turn à train around at Waterloo. These days, it is more like 40!

 

A deceased friend of mine, Jimmy Buttle, when he was young, had the privilege of setting the points on one of the Merchant navy,s as she pulled out of Waterloo with her first train. This must have been post war as he served on HMS Pepperpot (Penelope) during WWII .

 

His days working at Waterloo lead him to make a 5inch gauge live steam schools class (like a little motorbike he would say) and lead him to modelling (though more from a signalman's point of view rather than a scaled detailed model) Waterloo station in his attic (a massive layout). He had entire classes of locos running on it (including 17 Nelson's after he accidently brought an extra).