7 1/4" A3 flying Scotsman build progress

[a3lner]

Morning all. I am in need of sealing my hunslet smoke box after a major overhaul on her. Does any body no of any new type of sealant to uses or is it best to keep with the old school Many thanks tom

[gwr14xx]

Hi Tom,
I use Holts Firegum (car exhaust sealer paste) on the smokebox of my 5"g 9F. After applying it, I leave the loco unsteamed for about a week - by that time the paste has dried enough not to be affected by any water, and the first steaming cures it completely. I have run for the last 3 seasons without having to resort to resealing.

Regards,
Eddie.

[mr swarf]

Hi Tom,
I've used red heramatite in the past for this with no problems. It has now been rebranded as red hylotyte.

[a3lner]

Thank you for the help gwr14xx and mr dwarf I have a choice to make now

All the best Tom

[NickM]

Hi Tom,

I have used high temperature silicone on 5 engines i have built/refurbished and have had excellent results. The flexibility when cured (about 6 hours at room temperature) is a big bonus, it doesn't crack like fireclay or gun gum. Readily available on that well known auction site.

Regards,

NickM

[a3lner]

Hi all
I have just seen a Documentary ( episode 1) about flying Scotsman on channel 5 tonight. Just thought I would let you all no. All the best Tom

[a3lner]

Hi all am looking for a Full set of jim vass standard class 4 tank in 7 1/4 gauge
To buy outright or I can copy and will pay for the loan and cover expenses postage etc. I am wanting to start planning for my next loco build as I spend a lot of time in hotel rooms when working and I can start cad bits for it. Hope some body can help as drawing prices are high 🙁.

Thank you tom

[a3lner]

Hi all. This is a video of Dave smiths great model of a 7 1/4 decapod I had so much fun taking this around on Sunday afternoon hope you like it ps there is more videos coming of to our clubs you tube channel in due course. Will get one of Dave’s p2

m.youtube.com/watch?v=jh4WNrpvEWI

All the best Tom

[a3lner]

hello all just a quick one for you LNER fans... i have come across a boiler for a 7 1/4 p2 the boiler is new and comes with hydraulic test cert.. price is to good to walk away from as i get the casting to. but my question is will this p2 boiler fit on to my a3??? i no some lner boilers fitted different locos but not sure if this was one of them??? any help would be good, as a thick i read some where some time about they was the same but not sure

tom

[Deleted]

Hi Tom

I did a little digging through my books and online trying to answer your question. There are some obvious differences, whether any of these can be hidden under the cleading may need more research...The A3's had boiler type 94, either 94HP with the round dome or 94A with Banjo dome, I believe that the general dimensions are the same with the Banjo dome being positioned further back in comparison to the earlier round domed A3. The P2's used the boiler type 106

I can give these dimensions..

94 dia:
Barrel dia: 6' 5"
Barrel Length: 19'
Firebox casing length: 9' 5 1/2"
Barrel rings: 2

106 dia:
Barrel dia: 6' 5"
Barrel length: 18' 11 3/4"
Firebox casing length: 10' 9"
Barrel rings: 2

A couple of notes;

As can be seen, the diameter is the same, the barrel length is more or less the same, I believe the difference is internal due to thicker tube plates. The fireboxes are certainly different with the P2 having the larger, they both have the same width of 7' 9". Barrel rings are how many telescopic parts make up the barrel, both the A3 and P2 have two barrel sections, first being parallel and second tapered.

There are works drawings out there somewhere but I failed to find them so far, hope this helps a little...

regards

Pete

Edit: Just to add to this, the similar P1's used the type 94 boilers

[a3lner]

hi pete thank you for your help this loco sure does no how to give you an headache. the question is do i buy it and try to make it fit by hidden it under the cleading as i am wanting the banjo dome anyway. or bite the bullet and order copper and build my own???

[Deleted]

I would take measurements of the boiler itself to see what's what, compare it with an A3... it may be for a P2 but how close is it to the prototype, does it actually have the larger firebox? One deciding factor would be, is the dome in the correct position, you can't hide that under the cleading

Hmmm.. scrub that, I just took a look at the P2, I can't see a dome so it must all be hidden under the cleading?

[a3lner]

this is an up date picture of my flying Scotsman  well old picture but up dated on here.  will load new picture of her soon 

[Deleted]

nice work Tom.. she's looking great..

Pete

[a3lner]

Dec 5, 2018 20:42:38 GMT @greenglade said:

I would take measurements of the boiler itself to see what's what, compare it with an A3... it may be for a P2 but how close is it to the prototype, does it actually have the larger firebox? One deciding factor would be, is the dome in the correct position, you can't hide that under the cleading

Hmmm.. scrub that, I just took a look at the P2, I can't see a dome so it must all be hidden under the cleading?

pete   

i think i am going to have to bite the bullet and take the drive,, 12 hour round trip here i come may have to take the wife for this one night away and all that .   i no the bulider of the boiler but he can not find the drawings he build it to and can't get the sizes becasue of the cleading   he seems to THINK it will fit but this is why i am asking you.  something is in my mind about it and i think you have answered them pete.  but no arm in getting measurements fingers crossed 


tom  

[a3lner]

Dec 5, 2018 22:23:44 GMT @greenglade said:

nice work Tom.. she's looking great..

Pete

i just wish it looks as good as yours pete  

[Deleted]

I just done a check on axle distances...

A3 overall length, buffer to dragbox is approx 34' 5 1/4 "
P2 overall length, buffer to dragbox is approx 35; 9"

So 1' 3 3/4" longer
However, when checking the wheel distances, things are much closer;

The important trailing wheel to trailing driver centers is 9' 6" for both loco's, mean the curve of the running boards behind the rear driver is similar. The firebox seems to start in the same place for both classes with the P2 going further back to approx level with the trailing wheel back flange, the A3 stops a few inches after the center of the trailing axle.

Distance between trailing driver center and front bogie wheel center (only one bogie axle on P2) is again, very close. 26' 3" for the A3 and 26' 6" for the P2.

Looking at the drawings and the measurements I think it's safe to say that most of the extra length is after the trailing wheel centers with little differerances throughout the wheels, ok the P2 has an extra driving wheel, but it only also has a single bogie wheel.

BTW, distance from trailing wheel center to drag box is 4' 2 1/4" for the A3 and 5' 2 1/2" for the P2.

It seems clear that the boilers are mostly the same size except for the extension of the firebox which is all to the rear, the problem that I can foresee is how far back the backhead will be in the A3 cab with the P2 boiler fitted, I'm sure that it will fit, it's what it looks like that we don't know. IMHO this is the area that you'll need to look at most closely..

regards

Pete

[Deleted]

Dec 5, 2018 22:37:02 GMT a3lner said:

Dec 5, 2018 22:23:44 GMT @greenglade said:

nice work Tom.. she's looking great..

Pete

i just wish it looks as good as yours pete  

It looks bloody good to me mate...

Pete

[a3lner]

Dec 5, 2018 22:59:29 GMT @greenglade said:

I just done a check on axle distances...

A3 overall length, buffer to dragbox is approx 34' 5 1/4 "
P2 overall length, buffer to dragbox is approx 35; 9"

So 1' 3 3/4" longer
However, when checking the wheel distances, things are much closer;

The important trailing wheel to trailing driver centers is 9' 6" for both loco's, mean the curve of the running boards behind the rear driver is similar. The firebox seems to start in the same place for both classes with the P2 going further back to approx level with the trailing wheel back flange, the A3 stops a few inches after the center of the trailing axle.

Distance between trailing driver center and front bogie wheel center (only one bogie axle on P2) is again, very close. 26' 3" for the A3 and 26' 6" for the P2.

Looking at the drawings and the measurements I think it's safe to say that most of the extra length is after the trailing wheel centers with little differerances throughout the wheels, ok the P2 has an extra driving wheel, but it only also has a single bogie wheel.

BTW, distance from trailing wheel center to drag box is 4' 2 1/4" for the A3 and 5' 2 1/2" for the P2.

It seems clear that the boilers are mostly the same size except for the extension of the firebox which is all to the rear, the problem that I can foresee is how far back the backhead will be in the A3 cab with the P2 boiler fitted, I'm sure that it will fit, it's what it looks like that we don't know. IMHO this is the area that you'll need to look at most closely..

regards

Pete



pete that's interesting about the firebox as i have just spoken to the builder of the boiler about this and he had to make the firebox 3/4 (about he thinks)  from the backhead smaller due to the design of the boiler to get it pasted with the boiler inspector, this was due to the approved drawings for the boiler, so if this is the case the backhead is going to be in my fever of how in looks in the a3 cab, if i have read this right?     

tom  

[Deleted]

It's certainly going the right direction Tom...looking at the firebox length dimensions I gave earlier and dividing the difference by 8 (iirc 7 1/4" =1/8th scale)this gives a difference of just under 2"? So you may still be out by more than an inch...I'd still measure the boiler though, perhaps make a card template of the side profile and sit it on the frames...do the same with a cab side sheet (assuming the cab isn't made yet) and see what you have. I did this on my 5" when moving the smokebox back 1/8th to match the prototype.

Pete