Garden Railway Forum

DonW wrote: ↑Sun Sep 22, 2019 8:19 am One thing I dont quite understand why would you need to remove a firebox quickly can you not simply drop the fire?

The Sweet Pea boiler design isn't a conventional locomotive type boiler, it is based on the Bagnall drumhead design, which has a marine type firebox.

You can't drop the fire into the ashpan like a conventional loco boiler, as the firebox is cylindrical and surrounded by water. The only way to remove the fire from the boiler is to take off the dry backhead and rake the fire out the back of the firebox.

Regards,
Graeme

ps. This Wikipedia article describes the marine boiler type that the Bagnall boiler was based on....

https://en.wikipedia.org/wiki/Launch-type_boiler

Thanks for that. It would be a bit awkward simply dropping a fire in a boat.

Don

Here are a few photos to go with Graeme's response:

Did you spot the wheels in the last post?

These are for the tender and as you can see they need a clean!


I have tested removing rust using white vinegar (soaking the parts overnight) and it's proven effective so far, hopefully it will work on the wheels.

Here's the underside of the tender (paint needs stripping and parts cleaned up):


I don't know if I will ever use it, however, I am restoring it to test out my chemical blackening ideas for the loco.

First round of cleaning:


These will be chemically blackened so the finish doesn't have to be perfect.

First go using a proper four stage chemical blackening process, these parts are for the axle boxes on the tender:

Efforts have continued since my last response, however, my job keeps me busy and enthusiasm to post has lessened as I don't feel there is enough interest in posts of 'large scale' projects.

The tender frame was undercoated with grey primer before I owned it to protect the metal although surface rust had developed. I applied paint stripper over the frame and left it for 24 hours:


To aid grinding the chassis back to metal I dismantled it and got one of the buffer beams cleaned up (not a great picture, the metal is brighter than shown):


On the loco front, new commercially made safety valves by Blackgates Engineering have been fitted and steam tested. These are 'progressive lift' type which means they don't blow off violently like pop safety valves but still close quickly once pressure has been released:


Each valve has a locking ring so that once set to blow off at the desired pressure they cannot be tampered with unless the ring is unscrewed.

Also, the reverser has been refitted after extra notches were added:


And the firebox nuts have been replaced with knurled nuts so they can be easily undone by hand (with gloves) if the fire needs to be removed from the boiler quickly:

Good work Tom! Stick with it, forums are a great venue for recording a project

I'm pretty interested in this project. I just don't have much constructive input- but I watch out for new posts and read every one. I find the Bagnall "drum" boiler very elegant and does away with a lot of the tricky and high-stress bits like the mud ring and throat-plate.

Just for you two, I will carry on

The chimney as supplied was secured to the smokebox with this clamp (the clamp attaches to the bottom of the chimney inside the smokebox):


In practice, with the fluctuations of tempature and the movement of the loco on the track this clamp did not hold the chimney securely.

So, the smokebox was drilled and tapped to take BA bolts:

Great work Tom, looking really good!

Glad you are still with us Hugo as your introduction way back had many interests that you were planning to share?

Looking great, Tom

Also following your build as I help run my father’s 3 1/2” Penrhyn ‘Charles’ and L&B ‘Yeo’, so it’s nice to see some large scale on this forum.

Cheers

James

I'm watching too Tom, although I can't contribute to the thread I read each and every entry every day.... 'We are all different'..... (Life of Brian!)

As Peter said, I watch but have nothing to contribute, but it's interesting to see.
I'm sure the same thing applies to others as well.

philipy wrote: ↑Tue Feb 04, 2020 10:56 am As Peter said, I watch but have nothing to contribute, but it's interesting to see.
I'm sure the same thing applies to others as well.

+1, I love reading about these things, but acknowledge it's way beyond my skill levels and I couldn't contribute anything worthwhile.

I am still catching up with posting of past work on the loco to get you all updated.

The hand pump started leaking on the last running day at the club in 2019. When I took the pump apart I found this odd looking o-ring used on the ram (possibly PTFE round section?):


When I bought the correct size silicone o-ring and fitted it you can see in this picture that it protrudes slightly out of the groove on the ram:


The groove was found to not be the dimensions as per the drawing so it was adjusted. Now, the o-ring fits properly and the hand pump works although in use is a very slow method of getting water into the boiler so I decided it was time to look into fitting an injector!

Tom,

Not sure if you’re aware or not, but I discovered not too long ago PTFE in liquid form that you paint onto threads rather that using the tape which is a faff most of the time; it’s saved me a lot of time and it’s wonderful stuff!

Cheers

James

tom_tom_go wrote: ↑Mon Feb 03, 2020 10:32 pm Glad you are still with us Hugo as your introduction way back had many interests that you were planning to share?

Slightly off topic but yes I did, I still plan to in the future. It turned out that life and work got in the way of my plans...

Thank you for sharing your projects Tom. Your videos of Roundhouse locos with magnetic chopper couplings have given me great inspiration over the last couple of years. I'm currently waiting patiently for my slomo delivery from Terry.

Keep up the great work Tom

TheChestnutLine wrote: ↑Wed Feb 05, 2020 1:01 am Tom,

Not sure if you’re aware or not, but I discovered not too long ago PTFE in liquid form that you paint onto threads rather that using the tape which is a faff most of the time; it’s saved me a lot of time and it’s wonderful stuff!

Cheers

James

I agree with PTFE tape being a faff, it also degrades over time and could end up in places you don't want (boilers, valves, etc).

I have been using Loctite 290 with fittings on this loco which seals adequately but allows parts to be undo without using heat or hammers!