BR55/G8.1 Locomotive Project

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datman
Posts: 35
Joined: Mon Feb 17, 2020 10:10 pm

Re: BR55/G8.1 Locomotive Project

Post by datman » Fri Feb 28, 2020 3:48 pm

super7b wrote:
Fri Feb 28, 2020 8:51 am
super7b: you are running a Nigel Gresley? This is so similar to the BR55 in almost every way, how she run? strong runner? what gauge is she (5")?

I've run it for years on ground level continuous tracks and a portable track as well. Normally do 3 to 4 hours at a weekend on a 1.2 km track. Portable track 150mtrs long, up and down for around 7 hours, my back gives up before the loco.

It is 5" gauge, reliable, ultra reliable, very forgiving and yes, she feels strong. Had odd occasional problems with suddenly becoming shy of steam, found that the bottom row of tubes had blocked, rodded out and carried on. After a couple of times, fitted a stainless front to the grate to deflect the fire up and over and get a better spread of gases through all the tubes. never blocked since.
Boiler was built to Martin Evans' except I reduced the number of tubes to 14.

Not much more that I can say.
Thanks super7b,

Is the boiler built with a thermic syphon?

Ian

super7b
Posts: 86
Joined: Wed Oct 29, 2008 12:19 pm
Location: Beckingham, Lincolnshire, England

Re: BR55/G8.1 Locomotive Project

Post by super7b » Fri Feb 28, 2020 3:51 pm

Simple answer, no. I don't believe that there is any benefit to be gained in having on in our scale.

datman
Posts: 35
Joined: Mon Feb 17, 2020 10:10 pm

Re: BR55/G8.1 Locomotive Project

Post by datman » Fri Feb 28, 2020 4:59 pm

Hi,

This is my final compromise I think. The tubes maybe slightly smaller than some night recommend.
The small tubes have gone up to 1/2 OD and the superheater flues are 7/8 OD, the boiler barrel is 5 1/2 inch. I have tried to keep the firebox crown low as possible but allowing enough space for tubes. This current layout has marginally more tube area.
There is at least 1/8 space between tubes.
Boiler Tube Nest 2.png
I am think 5/16 tube for superheaters.

Ian

datman
Posts: 35
Joined: Mon Feb 17, 2020 10:10 pm

Re: BR55/G8.1 Locomotive Project

Post by datman » Fri Feb 28, 2020 4:59 pm

super7b wrote:
Fri Feb 28, 2020 3:51 pm
Simple answer, no. I don't believe that there is any benefit to be gained in having on in our scale.
Thanks.

Interesting that there are so many opinions out there. One would think that you could test this if one had the time and money!

Ian

datman
Posts: 35
Joined: Mon Feb 17, 2020 10:10 pm

Re: BR55/G8.1 Locomotive Project

Post by datman » Fri Feb 28, 2020 5:48 pm

Hi,

Does anyone chamfer the edges of the firebox plates?
Firebox Chamfer 1.png
Thanks

Ian

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gwrdriver
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Location: Nashville Tennessee

Re: BR55/G8.1 Locomotive Project

Post by gwrdriver » Fri Feb 28, 2020 6:08 pm

I don't do that, at least at that place. What I do is put a slight chamfer on the UNDERside of the lap, on the side I plan to feed solder to . . to give the solder an unobstructed entry point and draw it in. It also helps to leave the lap edge vertical on the solder feed-in side . . this essentially creates a stop, to butt the solder stick up against during the feed. When you've got many pounds of copper (£££) up to heat and need to get on with the job ASAP there tends to be some nerves involved and hands can get tired and shakey, and chamfering the outside could lead to the stick skipping across the joint and laying a blob of solder where it's not wanted or needed. I do however run a file over the outside corner to get rid of any sharp or wire edges.
GWRdriver
Nashville TN

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Builder01
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Location: Erie, PA

Re: BR55/G8.1 Locomotive Project

Post by Builder01 » Fri Feb 28, 2020 7:17 pm

Here's how I did my fire box and foundation ring. Boiler barrel is 5".
DSCN1162 - cropped.jpg
DSCN1162.JPG
DSCN1159.JPG
David

daves1459
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Joined: Mon Jun 07, 2010 7:58 pm

Re: BR55/G8.1 Locomotive Project

Post by daves1459 » Fri Feb 28, 2020 8:14 pm

datman wrote:
Fri Feb 28, 2020 5:48 pm
Hi,

Does anyone chamfer the edges of the firebox plates?

Firebox Chamfer 1.png

Thanks

Ian
I do on boilers with flanged end plated, but not in the mud ring area. I chamfer the plate flange edges from the top of the mud ring up to the crown sheet. The purpose is to keep the water leg flow area as open as possible. For two reasons, one to assist the water flow around the water legs then up over the crown sheet. Second so not to create chokes and pressure drops that will encourage debris in the water to drop into water legs and clog them up, also, hopefully, to assist the velocity of the water around the water legs during blow down and flushing. As an example consider the boiler in the picture ready for the installation of the mud ring. The water legs are 1/2" wide along the sides and back, 5/8" wide in front. The sheets are 1/4" thick. You can see there is a choke point in all four corners at the flange ends. The area width is reduced to 1/4" in the rear and 3/8" in the front. A 45 degree chamfer restores the flow area.

Dave
Attachments
DSC01989.JPG

datman
Posts: 35
Joined: Mon Feb 17, 2020 10:10 pm

Re: BR55/G8.1 Locomotive Project

Post by datman » Fri Feb 28, 2020 11:04 pm

daves1459 wrote:
Fri Feb 28, 2020 8:14 pm
datman wrote:
Fri Feb 28, 2020 5:48 pm
Hi,

Does anyone chamfer the edges of the firebox plates?

Firebox Chamfer 1.png

Thanks

Ian
I do on boilers with flanged end plated, but not in the mud ring area. I chamfer the plate flange edges from the top of the mud ring up to the crown sheet. The purpose is to keep the water leg flow area as open as possible. For two reasons, one to assist the water flow around the water legs then up over the crown sheet. Second so not to create chokes and pressure drops that will encourage debris in the water to drop into water legs and clog them up, also, hopefully, to assist the velocity of the water around the water legs during blow down and flushing. As an example consider the boiler in the picture ready for the installation of the mud ring. The water legs are 1/2" wide along the sides and back, 5/8" wide in front. The sheets are 1/4" thick. You can see there is a choke point in all four corners at the flange ends. The area width is reduced to 1/4" in the rear and 3/8" in the front. A 45 degree chamfer restores the flow area.

Dave
Dave,

I am thinking same as you, to have good flow around legs and not collect debris.

I think I will now increase the leg width at the front as well.

gwrdriver, I like your point about the chamfer on the inside edge, I have been wondering about getting the silver solder flow into the joints.

Builder01: thanks for the pictures, a good visual.

Ian

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gwrdriver
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Location: Nashville Tennessee

Re: BR55/G8.1 Locomotive Project

Post by gwrdriver » Sat Feb 29, 2020 9:14 am

I have adequate water leg circulation space on my current boiler (6"diam) but it wouldn't hurt to relieve those inside corners of the backhead and throat sheet per Dave's practice.
GWRdriver
Nashville TN

datman
Posts: 35
Joined: Mon Feb 17, 2020 10:10 pm

Re: BR55/G8.1 Locomotive Project

Post by datman » Sat Apr 11, 2020 4:47 am

Hi,

I hope all are doing OK in this weird time of virus lock down.

I was wondering if anyone can help me with interpreting these fastener rivet sizes etc?
These are original German drawings.
Fastener 4.png
Fastener 3.png
Fastener 2.png
Thanks.
Ian

Asteamhead
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Location: Germany, Duesseldorf

Re: BR55/G8.1 Locomotive Project

Post by Asteamhead » Sat Apr 11, 2020 7:08 am

Hello datman,
Sorry, but I'm not sure, which nos. are yours and which are shown in the original drawing?
All measures of the (prussian) drawings are shown in [mm] for sure. Thus I think of metric [M 20] or similar, rivets of 14 mm and bores of about 15 mm in diameter.
Back before founding of the DR which absorbed standard engines as the pr class G 8.1 as DR class 55.25, the threads might not be metric throughout yet. In later years all those small parts were normalised into standard metric sizes as M 6, M 8, M 10, M12, M 16, M 20, M 24 up to M 36.
Width of (old) nuts are about 1.7 x size M
Otherwise you could take one measure as reference and calculate the proportions.

Best regards
Asteamhead

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