New Build Night Owl - 4709 Begins

I have to say from the patriots point of view, we pay llangollen engineering a lot of money for the work done on our loco and Will continue to do so until we are completed. Not only do we do that but we also have things like members day (last year we bought down 110 people in the end) and we hand out llangollen leaflets from our sales stand all around the country so I think we do enough to warrant our place in the shed.

 

I can see the concerns that some may have with the construction of 4709 - similar concerns to the construction of a P2 in the future - over the size of the locomotive and the use it may have on or off the mainline.

However, the bottom line is that people are donating to 4709, seemingly at a rate of knots, which they probably wouldn't if you suggested an alternative loco of a better size for mainline or heritage railway operation - a Star or an Aberdare, say.

 

To give some idea of size, here is a close up photo of one, unfortunately on a scrap line albeit without tender.
47xx no.4706. Swindon scrap. 26 April 1964 | Flickr - Photo Sharing!

Look at the length of the smokebox!

Or one from an old ebay listing.
http://www.auctiva.com/hostedimages...522378086&images=522378086&formats=0&format=0

Full listing.
http://www.ebay.co.uk/itm/Railway-P...-2-8-0-Steam-Loco-/140655007882#ht_1940wt_883

 

Stick it next to a Duchess and it'll look rather small...

 

The smokebox on the prototype was even longer when originally fitted with a No.1 boiler!

I think that if people donated on the basis of their head and thus overall praticality for the main line the 5AT project would have taken off, but we all do with our hearts for various reasons and hence the popularity of the 47xx - I for one cannot wait!

 

A King doesnt look small next to a Duchess and neither will a 47XX. the coupled wheelbase is nevertheless quite long and i wouldnt be surprised if the results of the 'P2' research dont have some bearing on what this loco is allowed to do...

 

On the big railway only if NR says it can. It's their railway and they call the shots.
Have NR ratified where and where either P2 can't go yet?

 

Very similar to those two agreed Apart from the 20 ft coupled wheelbase...

 

The A1 Trust P2 chassis dynamics are being modelled using an industry standard computer package and the design will be tuned to try and achieve compliance with group standards etc. No idea what the 47xx boys are doing though.

 

The 4700 and the 5200 axleboxes and hornguides are the same components..Hence the the use of 5227s as a donor
The rear axlebox has built in side to side movement and the rear crankpins are spherical allowing them to follow this
Not sure if the 28xxs have this.
It has a 20 foot coupled wheelbase, same as a 42/52
will take 8 chains normal 7 slow same as a King Hall Castle
There are quite a few pics of 4700s running round the docks at Birkenhead
Restricted dut to its wheelbase ? I think not
The boiler is very close to Castle....and that is going to be the expensive bit

 

The photos of 47xx in the docks at Birkenhead will all show the locos on basically the same couple of tracks. They were allowed to cross over Morpeth dock bridge,drop off their train, then run round using an adjacent track. That was the limit applied to this class.

Bob.

 

Re the earlier comments about the 4700, 28xx's and 8Fs, do please bear in mind that the 28xx and 8F are not mixed traffic engines, with coupled wheels of 4ft 7.5 inches and 4ft 8 inches respectively.
The 4700s had (will have...) coupled wheels of 5ft 8 inches, which compare with say a Grange at 5ft 8 inches, and a Hall and Black 5 at 6ft 0 inches. To my mind this makes 4709 a much more useful mainline loco. Yes it does have a long coupled wheelbase, but as an earlier poster has explained, the rear axlebox allows for some play to make the wheelbase a little less rigid.

 

ish... the barrel (and thus tube arrangement) was King diameter but shorter, but the firebox was very close to the Castle. (or strictly speaking the reverse since the Std 7 came first).
The Std7 used the flanging blocks etc from the Great Bear, which were then reused on the King. There were proposals for a Std 7 boiler Star, but it wouldn't meet the weight limits, hence the Std8 (Castle) had the same firebox (later slightly altered) but a smaller diameter barrel.

Its an example of the wastefulness of the sudden BR rush to end steam that the boilers on the 47s were all under ten years old when scrapped. The GWR built 10 boilers in the 20s for the class when they were new, and no more were built until 1955-7, when another batch of 10 were built. They must have been very highly valued for a complete set of 10 (9 on locos plus one spare) to be built at such a late date.

Back in the day they were restricted to 60mph because the front end nosed about above that speed, so I imagine the new one will be restricted to 55 or 60.

 

Might it be possible to upgrade the side control on the pony truck to reduce the 'nosing', using similar ideas to how other locomotives were improved over the years? OK, it won't help with permitted maximum speeds, as coupled wheel diameter does that, per Group Standards, but it would help with crew comfort and a lessening of stresses both on the locomotive and the track.

 

Photo of the frames, and extension frames in the shed at Llan.

 

great bear replica next then

 

In answer to those who ask why dismantle engines to make a rebuild of a lost class, well,it says a lot that money is there to rebuild a 47xx and there was no interest in restoring the donor loco, that should be your answer.
Its not like any of the donor locos had a realistic chance of getting restored, whilst at glamorgan, nothing happened , no restoration was started on any of the hulks, most are only a boiler, frames and wheels.

In my view to build something that did not escape the cutters tourch is worthwhile, i would bet a gala with a visiting 47xx, saint or grange would be more interesting than another 41xx tank and as long as NR can gauge it , this big beastie has got to be a must over the devon banks , single handed