[steamrailuk]

Hey everyone, I came across a loco project a while ago that you would be very interested in. The project is called the 5AT and will be the most advanced, efficent and possibly even the fastest steam loco in the world if given the chance. Loosely based on the BR 5MT 4-6-0, this loco will incorperate many of the advances in steam technology from locos such as SLM class 52 or the The Red Devil

Heres the link to the 5AT project to find out more http://www.5at.co.uk/

 

[steamrailuk]

do you guys think this loco is capable of taking the speed record if they decide to try for it?

 

[steamrailuk]

QUOTE (BRITHO @ 15 Aug 2008, 12:46) <{POST_SNAPBACK}>I'm sorry but I have to agree with 34C on this one. The chances of this project ever coming to fruition are, in my opinion, as likely as me winning the Euromillions. I really don't see the point of the project as it is unlikely it would ever be allowed to run scheduled services due to lack of infrastructure.

Regards

I understand what your saying but i'm sure the same thing was thought about the tornado project when it was first concieved or many others like the Saint, County, Clan and B17 Projects.

 

[steamrailuk]

QUOTE (34C @ 15 Aug 2008, 21:04) <{POST_SNAPBACK}>The spec correctly acknowledges the need for large consumable supplies, and a large bogie tender is provided for . But this places a constraint on the loco length to stay within the 70' turntable limit. Here's where completely rethinking the traditional steam loco format would really pay off. It is going to be oil fired, so provide full servo automation of all controls, and abandon the traditional cab as the driving position. Place driving positions both ends, just as on a diesel or electric. The improved forward outlook alone justifies this. That means the length restriction is far less severe, as with the loco fully reversible there is no need for turning. With a compatible control system the loco could also push a DVT equipped set. The advantage for rail tours with pressure on minimising turn round, and integration with the other motive power should be obvious.

Integrate all that, and a UK version of the Hiawatha 4-6-4 suggests itself, 4,500 dbhp, six axle tender, roughly 100 ft long, good for 120mph with a 300T payload - roughly an HST equivalent. Now that would be exciting.
Are you suggesting a loco similar to the Leader class loco built by Oliver Bullied?

 

[steamrailuk]

QUOTE (34C @ 16 Aug 2008, 10:24) <{POST_SNAPBACK}>Oh no, heaven forfend! There was just too much 'new and untried' in that rethinking of the format to be successfully developed when steam was still in mass production and operation, with thousands of men daily practising the related engineering expertise. Not a chance of developing anything that far from the basic Stephenson format now. This lack of mass experience and the developed expertise that results is a serious issue for any such project, as the Tornado build demonstrated. Even the best people, when they are few in number, need a lot of time to simply get all the work done right.

So, this is about making the absolute best of the Stephenson format. If you want a fast reliable and powerful steam loco, start from the existing 'best in class' examples and develop that. No doubt about it, for really fast powerful and reliable simple locos, best in 2 cylinder were machines like the Niagara 4-8-4, and Hiawatha 4-6-4. In shrinking these to British loading gauge, an extra cylinder is required. (I have spoken to enginemen who worked Britannias, and while they all regarded it as a good tool, the hammering it handed out to them was not well liked!) BR discovered that the cheapest big engine it had (build, maintenance and operating cost) was the Peppercorn A1. There's your base platform for development - and BONUS! there is current experience of building one. An extra trailing truck wheel might well be a good idea to keep the axle loads low enough (and it will help in another way), so probably a 4-6-4.

So what your suggesting would be like the other locos i've posted on this link, SLM class 52 and the red devil. Start with an existing donor engine such as a 5MT/ Black 5/ or any other BR Standard and by using as many parts as possible, modernise the design.

 

[steamrailuk]

QUOTE (34C @ 16 Aug 2008, 18:47) <{POST_SNAPBACK}>The same process, but start from the absolute best in class for the type of work envisaged. The BR5 was a very lacklustre design: poorer than both the Black 5 from which it was developed, and the much cheaper B1 (BR's own data). If the intention is to build a steam loco for high speed service capable of integration into current scheduled operations it will need a lot of power to take a realistic payload: 4,000 drawbar horsepower would be a minimum. The proven express designs to study are the final generation of US express superpower which actually demonstrated this capability, and the best in class the UK can offer which would be the Peppercorn A1 and DoG as development platforms. It's a lot easier to do a 100% stretch from these 2,000dbhp designs, than 200% from the 1200dbhp of a BR5.
That does make sence about using the best in class as a template. surprised that the BR 5MT was a poor design as i though it was a more robust version of the black 5 and the B1 was a more efficient design as i though LNER locos were generally very refined, finely tuned machines, not very easy to maintain but that may only be true about gresley locos and not thompson or peppercorn.

the idea about using locos such as DoG and the A1 as development platforms with american practise incorperated into the designs is a good idea, but i'm not so sure if they would have problems with route availabilty. wouldn't a scaled down version of those locos be better?

 

[steamrailuk]

QUOTE (34C @ 18 Aug 2008, 14:55) <{POST_SNAPBACK}>Absolutely, you have to 'scale down'. The Great Northern A1 was largely inspired by the Pennsylvania Rail Road's immensely successful K4 pacific: Gresley took the key features which delivered this loco's performance and effectively scaled it down to produce a loco capable of fitting in the UK loading gauge. This became the platform to develop the A3, A4, and Peppercorn A1 pacifics, and was also where Bulleid learned his craft before leaving Doncaster for the SR to build further pacific developments. This pacific chassis stretches naturally to a 4-6-4, and maybe a 4-8-4 or 4-6-6 chassis, and definitely has the potential: in the US 4-6-4's could achieve over 5.000 dbhp, Chapelon had 5,500 dbhp out of a 4-8-4 (still too big for UK loading gauge) but somewhere in the 4,000 to 4,500 dbhp range should be achievable on a UK 4-6-4.

I'm sure the 4-6-4 design should work well in the uk remember the LNER "Hush Hush" and the proposed Stanier "Admiral" classes.

Considering all the castings and plans for 60163 Tornado are available and since Tornado and Duke of Gloucester are the two most advance steam locos in the uk; it would be interesting to see an advanced 4-6-2 or 4-6-4 variant of Tornado combined with the advances from the Duke of Gloucester.

 

[steamrailuk]

QUOTE (34C @ 18 Aug 2008, 14:55) <{POST_SNAPBACK}>A further challenge will be the frame strength, rod sections and bearing areas required to stand the 200% increase in piston forces: US design to handle these sort of power densities resorted to a cast steel frame with integral cylinders; and that came with a mighty weight penalty. Every single one of the advances proposed for 5AT has to work for the project to succeed, it is an awful lot to ask for, particularly when working off a base platform that was apparently pretty much on the limit.

Is that the reason why american loco's have very large coupling rods compared to british loco's?

 

[steamrailuk]

QUOTE (34C @ 18 Aug 2008, 20:49) <{POST_SNAPBACK}>Yup. On the final US maximum power designs the power that had to be transmitted, is at about a 3:1 ratio: 6,000hp as compared to 2,000hp in the UK.
thanks for that, always wondered about that on american locos. What do think about my suggestion for a combined Tornado design with the advances made in Duke of Gloucester as a development platform for a modern steam loco

 

[steamrailuk]

QUOTE (34C @ 18 Aug 2008, 22:56) <{POST_SNAPBACK}>If you have that kind of ability and energy, while building an example of an obsolete form of railway traction would be fun, I cannot help but feel that working on power generation might actually be more useful for society.

Unfotunatly I dont have that kind of expertise, it was just a suggestion as you said it would be a really big challenge to build an advanced steam loco from scratch rather than develope and existing design.

 

[steamrailuk]

34C I was wondering since you have a better knowledge of american locos than me, I was wondering if you could clear something up for me.

I was looking on the net and I came across a video of the Chesapeake & Ohio 614. In this video and on its website co614 it claims that this loco can produce 5000 horsepower and to my anstonishment it can reach 120mph. Can a loco of this size be capable of running almost as fast as Mallard?

I know locos that have small diameter wheels are capable of high speeds as I've heard stories that Evening Star could haul expresses up to 90mph, but is it possible to reach 120 without causing serious damage to either loco or track?