5AT Group Complete Project Feasibilty Study and start fund raising.

So why Boxpox wheels ?

Are these superior to Spoke wheels ? (or Disc for that matter)

 

I couldn't find an answer to your question on the website, but here's a page with the drgs and solid modelling of the wheel options ... http://5at.co.uk/index.php/engineering/drawings.html

 

Presumably, as with many things, it is a compromise, in this case between weight and strength (and cost), especially as the wheels are all unsprung weight. Wardale's preference appears to be the Scullin type as used on the NYC J3a Hudsons, which no doubt are lighter. However, Victorian Railways seems to have rejected all of these options in favour of the SCOA-P type for the R Class 4-6-4s.

 

I simply cant make my mind up about this project. But when I have some free time ray: I will be reading the website in detail.

I love the idea of developing the steam engine to its 'ultimate' form. However, for me the project must have the following aims in order to fully win me over:
1) Continuous development - i.e. if once its built dont stop - continue to find ways to improve it
2) Planned for worldwide operations (if possible with regulatory bodies) - I dont want to see it solely in the UK potentially taking work of 'traditional' steam locomotive - I would like it to be a flagship of British engineering, much like Concord (ok so I suspect much will be build abroad but thats not the point), to advertise our original idea to the world again. On that subject; for livery what about a tasteful interpretation of the union flag?
:target:

 

Regardless of the livery, a complete package could be created of loco and coaches. Chances of acquiring Mk4 sets (most favoured option) being the most modern available for locomotive traction may be low, but some good late Mk3's ( a poor second) are around. Loco and set of coaches available as a total unit in the same livery. That would create a superb brand image for 5AT and set Joe Publics imagination going.

 

Why are Mk4s considered the preferable option? I thought standard wisdom was that the Mk4s were despite being newer, inferior to the Mk3.

 

Mk4's simply because they are the most recent and fit closest to the principle of 5AT. Don't expect them to design a new set from scratch and buying second hand would be a less expensive option.

 

OK - nice idea, but where's the power for the ETH and aircon etc coming from? I'm not aware that the 5AT group have addressed this issue yet - will have to trawl the web-site again .....

 

It would be interesting to see what Network Rail would make about this proposal and seeing how the loco would fit in with all their regulations/standards etc. Also if its going to be built from scratch, surely a bigger loco would be more viable rather than a 4-6-0 design, maybe something like a 4-6-2 or even a 4-6-4 possibly?

 

I believe the groups view is that the 4-6-0 would have sufficent power to keep to a railtour schedule and have performance in reserve, so that the expensive of a bigger loco would be needless.

 

Some of the liveries proposed by members of the public, do show i in a better light.

Once concern, perhaps a stupid one is, on most rail-tours enthusiast focused or not, most preserved railways in summer, where do most of the punters gather on the platform? Round the cab, peering into at the controls of the mystical beastie and the guys who command it, requests to go on the foot plate, pictures of kiddies on the footplate etc.. Sort of difficult with that very enclosed cab and firmly shut door thats just begging to have a "Private no unauthorised access" sign on it.

 

On the size of the loco, I guess a 21st Century 4-6-0 could and should be as powerfull as pacific (helmet on and diving for the trench!) But if we look at car engine advances over the last 60 years we have smaller engines producing far greater power than larger ones of the day. Seems to stand to reason that Steam could be the same.

On access to the cab, I would think that PR would take over and access would be granted in the time honoured way. I reckon they will want to show off what they have and milk the publicity as they need more charters and passengers.

Wonder if we will have a re-run of London to Edinburgh on Top Gear with modern road vehicles?

 

... but a boon in winter. We had a fully enclosed cab on the ex-Swedish WD when it was running - very popular up the Valley in winter. As for summer, I think the idea is that the boiler will be insulated to a higher standard than is traditional, and the oil-firing means no fire-hole door radiation either. They must be confident as there are radiators spec'd for the cab!

 

The concept of the 5AT produces a lot of tractive effort. Due to its 4-6-0 arrangement, however, all that power can only be transferred to the rails without slippage by means of liberal use of sanding. Yes, that's what they say on their website, "semi-continuous light sanding... when long stretches of bad rail are encountered" (i.e. when it rains).
Eh? High performance dependent on sanders? And has any work been done to investigate the chance that the resulting film of gunge on these "long stretches of ...rail", or subsequently dried sand on the trackbed, might compromise other systems using the the same track, like bogie wheels powered by motors slung under coach bodies, as in the Class 180 Adelante and many other modern DMUs and EMUs?
Why have they not opted for a loco with eight slightly smaller coupled wheels instead? Because of the higher demands on (and hence cost of) the motion and cylinders that would be needed for fast running? Because the hammer blow would be unacceptable to the track owner?

It seems to me that the 5AT might be pushing the physical limits of the Stephensonian steam locomotive. Perhaps pushing them too far for its operating environment to accept.

 

Article about this in the current (June 2010) issue of 'The Railway Magazine'. However, nothing said about how they will obtain the claimed efficiency and power twice that of a BR or Stanier Class 5 4-6-0. Can't see it myself.

 

Can't see it or don't want to see it? 40ihp per ton of locomotive weight has been achieved before and the fact that none of the standard classes could achieve this sort of a figure indicates that these designs were simply not good enough. The benchmark figure of 40 ihp per ton was set well before the designs even came off the drawing board. The fact that there were large numbers of Black Fives does not mean that they were anything particularly special, they did a job and served a need, end of story. Consider then that 20 years after the class was introduced we were still building what was fundamentally the same design having learnt little or nothing about improving efficiency or power output in all that time. What could and should have been designed as a BR standard medium sized mixed traffic locomotive ought to have consigned the earlier type to a steady process of withdrawal.

 

Can't see it.

Compared with BR Standard 5MT, cylinders 1.2" smaller diameter, OK stroke 2.5" more. Boiler pressure 80 psi more, granted, but 450 degrees C superheat achieved by German 4-6-2s and 2-10-0s as long ago as the 1930s. Grate area the same. Oil burning a little more evaporation, but no one is kidding me that you'll get a 'Duchess' like evaporation from a Class 5 boiler.

So where does the better than a 'Deltic' performance come from? Not forgetting the small matter of applying the power to the rails with half the number of driven axles.