LBSC's Doris versus the Code

[Deleted]

On advice from a SASMEE colleague I add something to the water and left it overnight.

Could you please clarify this for my curiosity - did you just top up the water or did you put a Radweld type sealant in ?

[jma1009]

Fosters XXX lager?

well done brian - looks like you are almost there, and mission accomplished!

cheers,
julian

[GWR 101]

Hi Brian, glad to see that you have resolved the problems with the boiler test. You have my sympathy regarding the amount of time you have spent pondering this problem, I have spent the best part of 2 months putting off drilling the holes in my boiler regulator bush. Eventually decide to go the opposite way to you and went for 8 x 8BA. Stainless cheese head screws as there was not a lot of room and I didn't feel competent to modify the bush. Regards Paul

[steam4ian]

Julian.

One piece of advice. We Ozzies don't even drink Fosters let alone trust it in our boilers. Neither should you.

Ian

[runner42]

Jun 4, 2015 23:02:39 GMT steam4ian said:

Julian.

One piece of advice. We Ozzies don't even drink Fosters let alone trust it in our boilers. Neither should you.

Ian

Ian I thought you owned the brewery.

Brian

[runner42]

Jun 4, 2015 9:39:08 GMT michaelw said:

On advice from a SASMEE colleague I add something to the water and left it overnight.

Could you please clarify this for my curiosity - did you just top up the water or did you put a Radweld type sealant in ?

Michaelw it was to add some particulate matter to the water to seal the tiny leaks. It is probable that the leaks would have sealed themselves with the impurities in the water after a time, this was to speed up the process. What I added was some dirt, more specifically clay soil from the garden applied pressure and left it overnight.

Brian  

[steam4ian]

Please note that only Australian dirt will work.

[runner42]

Thanks Julian and Steve.

Julian your boiler construction for Boxhill was straight forward and it showed us how it should have been done. That I guess comes from experience to plan the job and in doing so be aware of the pitfalls. I did a number of things wrong, the greatest mistake was build order. Prematurely silver soldering the smokebox tubeplate to the barrel and the firebox doorplate to the inner wrapper. But in my defence I think that the 3 1/2" gauge LBSC Doris' boiler in accordance with the code, required inter alia staying in the crown area with its narrow aperture and deep firebox, needed a bit more skill than required for other wide aperture firebox boilers. Girder stays are more easily undertaken.

Steve yes these problems tend to occupy our waking hours. My wife was greatly pleased that I have finally cracked it, she witnessed many times me filling the boiler, emptying it and saying it's still leaking, she was feely sorry for me, but marvelled at my patience to keep trying. Well your selection of screw size and PCD was optimum based on the diameter of your regulator bush, which being a screw type regulator required a bigger aperture and therefore bigger bush. I should have been aware of the potential problems of trying to produce 8 x 6BA screws in a bush of only 13/16" diameter, I was lucky that my modification worked.

Brian 

[Deleted]

Thanks for clearing that up Brian .

Dirt we can live with but as you know some sealants are positively dangerous when used in boilers .

Not without precedent in full size - Porridge Oats was apparently the favoured material .

This is going a bit off track but you mentioned that some of your difficulties arose from assembling boiler parts in the 'wrong' order  .

In the real world the assembly order for any safety critical equipment would not be left to chance - there would be a build schedule provided as part of the drawings and technical specifications . I am certain that drawings supplied to model engineers would be improved greatly and save on a lot of wasted work and disappointments if they had more information about how things are supposed to go together and what fits are needed for particular assemblies .

Regards ,

Michael .

[GWR 101]

In the real world the assembly order for any safety critical equipment would not be left to chance - there would be a build schedule provided as part of the drawings and technical specifications . I am certain that drawings supplied to model engineers would be improved greatly and save on a lot of wasted work and disappointments if they had more information about how things are supposed to go together and what fits are needed for particular assemblies .

Read more: modeleng.proboards.com/post/new/9668#ixzz3cCfOAxDe

I believe most of us would second that, and it would certainly make things a lot easier. I can't really see that happening, but I live in hope. Regards Paul

[runner42]

That reminds me when I first arrived in Adelaide in 1975 I would not have needed to add dirt to the water it was already there, it came out of the tap a ghastly brown colour, plenty of solids. It was the only place in the world where airlines would not replenish their potable water stocks.

Brian 

PS Porridge Oats eh? That is our breakfast of choice, I daren't use that just in case the wife sees me taking it to the shed. It is remarkable that porridge oats is a good caulking medium for boilers, whereas it doesn't contribute to low density lipoproteins (bad cholesterol) in fact studies indicate that it reduces it.

[Deleted]

Hi Brian ,

Mention of natural mud in your water supply took me back to a geography lesson of many years ago on the Australian river systems . I was fascinated by the seasonal changes that some of these rivers went through - anything from dry bed to deep water channel or flood plain depending on that years rain fall .

Must have been difficult living in some of the inland settlements where water supply for agriculture and other purposes was so seasonal and uncertain .

(As for the creatures that come out of the mud sometimes - we won't go there) .

Specially designed shallow draft steam boats could apparently work far up the flooded rivers .

Just looked up the Murray river steam boats - similar to Mississippi ones but possibly shallower draft ? - and was pleased to see  that some are preserved and that some modern Diesel versions are still used commercially .

Excellent documentary once showed smaller cargo versions of the steam boats - delightfully quaint and looking impossibly top heavy when loaded with goods .

They make a noise like the 'Puffer' boats did on the Scottish rivers and Lochs though totally different in design .

Not sure but I think that a special ship's masters ticket was needed before anyone was allowed to take a commercial boat on the Murray because of all the particular navigational hazzards the river had .

Judging from state of boilers shown on some boats in documentary I think they used a lot of Porridge Oats as well !

Michael .

[Jim]

The Murray-Darling paddle steamers were side wheelers rather than stern wheelers as on the Mississippi. Some were snagging boats for clearing the channels of submerged and fallen logs and snags brought down in the floods while others were used for towing large barges loaded with bales of wool. The steam power plants were basically a portable engine with the crank shaft extended either side through the hull where the paddle wheels were attached. The National Museum of Australia here in Canberra is host to the PS Enterprise, you can see the details here;

www.abc.net.au/local/stories/2014/03/11/3960740.htm

A string of river ports developed along the Murray Darling doing a bustling trade until the arrival of the railways.

We are actually spending our 50th wedding anniversary cruising up the Murray River on a modern paddle steamer, the Murray Princess based in Mannum SA. It's very much in the style of the big Mississippi stern wheelers. It should be fun 

Jim

[runner42]

Many builders of locomotives on this forum often make reference to the full size version, perhaps to add additional detail not incorporated on the original design of the model but apparent on the full size version. Well I thought I should join that set. In trawling through pictures available on the Internet I have noticed that there is a large pipe running from the smokebox to the cab on the driver's  side of the boiler. What is this for?

Brian

[Shawki Shlemon]

Being an English engine , some from UK will know better than my guess , It could be a vacuum supply for brakes .

[steam4ian]

Brian.

It is the exhaust pipe for the vacuum ejector. In the photo you can just see the ejector body which is rectangular and mounted just in front of the cab. You can also see the brake pipe leading down from it.

Coincidentally I was just reading about ejectors last night in a Book about Crewe works.

Ian

[steam4ian]

Michael

Jim has given a fairly factual account of the Murray Darling river boats. I know of only two that were stern wheelers, "Captain Sturt" and the "Melbourne".
As Jim says most boats were powered by a package engine, as opposed to portable. A wood fired locomotive type boiler with a two cylinder engine mounted on top, sometimes with compounding. Drive to the paddle shaft was by gears or occasionally by leather belt sometimes with wooded cleats attached to it. A few steamers had an inclined cylinder each side of the boiler much like a loco set up, see PS Industry, with cranks and eccentrics on the paddle shaft. In the days of the steamers there were ample quantities of a hard wood called River Red Gum (Eucalyptus Camaldulensis) which was a very suitable fuel for the boiler; draft was natural rather than forced.

Most cargo was carried in barges towed behind the steamer. Each barge had to be steered in order to negotiate the rivers' bends and shoals.

There are many stories of boats being marooned up rivers when the water level fell and waiting up to three years until the river rose enough for them to sail out.

Ian

[runner42]

Thanks Ian and Shawki,

I understand that the vacuum exists in the smokebox and that an ejector works on the same principle as an injector, but what is being ejected?

Brian

[steam4ian]

G'day Brian

The air is ejected from the train pipe.
The continuous braking system used in the UK and formerly in Tasmania and WA is a vacuum type system. It is a fail safe system which releases the brakes by exhausting air from the train pipe down to about 21 inches of mercury. Each vehicle has a brake cylinder with upper and lower chambers with the piston in the middle. The lower chamber is directly connected to the train pipe and the upper chamber by means of a non return valve. Vacuum in the train pipe also exhausts the upper chamber. To apply the brakes the driver admits air to the train pipe thus raising the pressure and putting a pressure difference across the piston in the brake cylinder and applying the brake shoes to the wheels. To release the brake the ejector is turned on to pull the vacuum again. There are two ejectors in the assembly; the small ejector just maintains the vacuum to keep the brakes released whilst the large ejector can quickly restore the vacuum when releasing the brakes.

The ejector exhaust is directed up the funnel so as not to spoil the "vacuum" in the smoke box.

Ian

[jma1009]

hi brian,

your boiler is a lot more complex than my 'Boxhill' boiler as yours has a tapered barrel and belpaire firebox. ive made a few of that type, but one reason for building 'Boxhill' was the simplicity of the boiler!!

so you have done extremely well!

cheers,
julian