A new locomotive arrives on the railway

[dunnyrail]

I believe its one made by Wee Bee locomotive works, aka Jim Sanders and sold thru The Train Department over here in the USA. The stock RH ones want to weep constantly long before proper blow off pressure. Jim's blow off and snap closed, just as a safety should. I will know if its one of his for sure one of these days when we get together to steam again. He lives about 1.5 hours from me. I will see him more often once train show season starts up as he has a portable layout that we all steam up on at shows.

Had a look at the TD site, problem I have is that Roundhouse Locomotives are set for 40psi and the Wee Bee's appear to be only for 60psi. Now I know that a loco is tested at a higher preasure but I am not sure about them running constantly at 50% great preasure. You could perhaps ask Jim about that. I also note that there is an adapter to fit Roundhouse so that may be the clue for your loco.

Any comments anyone re running RH loco's 50% over working preasure?
JonD

 

[stockers]

Any comments anyone re running RH loco's 50% over working preasure?
JonD

Bang!

 

[TLR]

Copper tube as used in the plumbing industry

http://www.engineeringtoolbox.com/copper-tubes-dimensions-pressure-d_84.html

You will see that 54mm dia tube has a maximum pressure use of 392 psi with a 1,2mm wall thickness Table X
as the Fowler is smaller in dia and thicker wall then a higher pressure should be ok, Accucraft run their boilers at 60psi, incidently the copper tube is rated at C106 the same as the boiler copper

Shaun

 

[dunnyrail]

Bang!

Alan 16mm Boiler Testing is done at twice the normal working pressure on Hydraulic kit.

Copper tube as used in the plumbing industry

http://www.engineeringtoolbox.com/copper-tubes-dimensions-pressure-d_84.html

You will see that 54mm dia tube has a maximum pressure use of 392 psi with a 1,2mm wall thickness Table X
as the Fowler is smaller in dia and thicker wall then a higher pressure should be ok, Accucraft run their boilers at 60psi, incidently the copper tube is rated at C106 the same as the boiler copper

Shaun

But still not sure that normal running with the Boiler at 50% of its Blow Off pleasure is a good idea, lovely flatulent safety valves or not!
JonD

 

[Rhinochugger]

Alan 16mm Boiler Testing is done at twice the normal working pressure on Hydraulic kit.


But still not sure that normal running with the Boiler at 50% of its Blow Off pleasure is a good idea, lovely flatulent safety valves or not!
JonD

I'm with Stockers - I value my eyebrows, facial features and other working parts

Anyway, if the safety valve's blowing you've got too much pressure and have wasted gas

 

[Paul M]

Yes, 2 of those. I dont know what kind of glue as not much sticks to LGB plastic. The design of those brass check rails is that glue isnt really needed. Anyways, here is a video of Fowler running on my railway. I just removed the turnouts that will connect to the yet to be built extension loop till I am ready for them. Mike

Great video & layout, but please please get a fence up quickly, they don't bounce anywhere near as good as they go round!

 

[dunnyrail]

I'm with Stockers - I value my eyebrows, facial features and other working parts

Anyway, if the safety valve's blowing you've got too much pressure and have wasted gas

Too true re the blowing off, gas valve clearly in need of turning down some. I guess it needs to be higher to maintain the 60psi.
JonD

 

[artfull dodger]

That was early in the run as the tank was getting warmed up. I turned it down after I took the video. With the tight curves and a slight grade at one end, I have to keep steam up to run slowly and not almost stall at one point. I am torn on whether to get a slomo for it or not. They are not cheap and will be very visable on this model since there are no side tanks to somewhat hide it. I will look into some type of catch rail later this week or next. Pretty busy with tractor related stuff this week, have a big show on Friday I will be at. Mike

 

[dunnyrail]

The Slo Mo may be a bit visible, but you will never regret the quality of running. You could partially cover it with a plate on top as I am doing with my revisions whilst I rebuild my Jack.

Shown minus Side Tanks during rebuild. Cover plate is immediately behind the Smokebox. It could go the full length to hide the SloMo which as I recall sits over the rear two driving axles on the Fowler.
JonD

 

[TLR]

I'm with Stockers - I value my eyebrows, facial features and other working parts

Anyway, if the safety valve's blowing you've got too much pressure and have wasted gas


Yet we rely on a glass tube to tell us how much water is in the boiler

Shaun

 

[Rhinochugger]

Yes, although my only steamer, an Accy Shay, cannot be re-gassed while the burner is alight. I've seen it written that the manufacturers design the things so that the gas runs out before the water.

However, I agree, and I rely on the sight glass to set the level before firing

 

[dunnyrail]

Yes, although my only steamer, an Accy Shay, cannot be re-gassed while the burner is alight. I've seen it written that the manufacturers design the things so that the gas runs out before the water.

However, I agree, and I rely on the sight glass to set the level before firing

Re gassing before Water runs out is frought with issues. Something I never do as my Roundhouse all end at pretty well the same time, yes I know you can get refill valves but I find 20-25 Minutes sufficient run. As for my Peter Angus Locomotives, the Gas does last longer than the Water so contstant small top ups is the name if the game. Sight glasses are tricky at best but do show water kevel better with a diagonal line at the rear side as is sometimes done in the real thing.
JonD

 

[Rhinochugger]

Re gassing before Water runs out is frought with issues. Something I never do as my Roundhouse all end at pretty well the same time, yes I know you can get refill valves but I find 20-25 Minutes sufficient run. As for my Peter Angus Locomotives, the Gas does last longer than the Water so contstant small top ups is the name if the game. Sight glasses are tricky at best but do show water kevel better with a diagonal line at the rear side as is sometimes done in the real thing.
JonD

Yeah. on the big Accy tender locos, with the gas tank in the tender water bath, it's OK, but where the tank is close to the burner it's an absolute no-no as the gas is heavier than air - Kerbooom !

(Which takes us back to the facial features, working parts etc etc )

 

[Rhos Helyg Loco Works]

A few quick points:

- The gas tank on any loco should not be refilled while the burner is lit. Filling the tank would cause a quantity of liquid gas to fill the burner and so cause a huge amount of heat and flame with spectacular, dangerous and expensive results.

- If you are a UK-based member of the 16mm Association then I'm pretty sure that running your loco at 50% over the manufacturer's recommended and certified boiler pressure would invalidate your insurance cover should an incident occur. However, having another boiler test and getting a new certificate with both the higher working pressure and consequent higher test pressure shown may get around this problem, but please do check with the Association's Technical Officer if you wish to do this.

- Most coal-fired Roundhouse-based locos run at 60psi, but they have non-Roundhouse boilers that are specifically designed to take the higher pressure.

- Running a loco at 60psi will wear out the mechanical parts much quicker than when run at 40psi. In particular, the slide valves and their faces will suffer.

- A safety valve is exactly that ... it is there for safety. It is not a pressure indicator, most locos have a pressure gauge for that. If blowing it will lose more water (and consequently fuel) than when the loco is working flat out.

- I have yet to come across a safety valve that cannot have its release pressure reduced.

- A boiler empty of water cannot explode, no matter how hot it gets. It may well be damaged though.

- I recently fitted a Slomo to a Roundhouse Jack for a customer. Beautifully made, straight-forward to install and worked as it should, but I would never fit one to any of my own locos due to the increased mechanical load that it exerts and the noise it makes.

 

[stockers]

Alan 16mm Boiler Testing is done at twice the normal working pressure on Hydraulic kit.



JonD

For a very good reason. Your suggesting reducing the safety level by a half - that's massive.
BANG!

No it probably wont - but it might!

 

[Rhinochugger]

For a very good reason. Your suggesting reducing the safety level by a half - that's massive.
BANG!

No it probably wont - but it might!

MMmm, and structural engineers work to a safety factor of 3 when designing buildings.

When you see a crane with SWL 100 tonnes, has it been tested to just 100 tonnes?

The safety factor in design is exactly that - the safety factor; remove it, or reduce it and what have you got?

In the case of steam engines, 16mm or otherwise, Kerbooom!

I refer the honourable gentleman to my earlier comment about facial features and working parts

 

[stockers]

I believe a lifting device is tested to FIVE times its stated limit. Even a towing device is tested to 3 times its limit.

 

[dunnyrail]

Tony makes a very good point that I had forgotten, you can adjust the safety valve. It is a screw that can normally be adjusted with a pair of fine tweezers. I used to do this regularly when I tested Boilers for the Bedfordshire 16mm Group. A turn or two is all that is required, wish I could remember which way I am pretty sure that anti-clockwise will reduce the preasure. But please wait for some confirmation on this before attempting. You do not want to be changing the Fowler Preasure up to 80 PSI!
JonD

 

[TLR]

To increase pressure screw clockwise to reduce pressure anti clockwise and to quote Tony

A boiler empty of water cannot explode, no matter how hot it gets. It may well be damaged though.

Shaun

 

[Rhinochugger]

I believe a lifting device is tested to FIVE times its stated limit. Even a towing device is tested to 3 times its limit.

It's a long time since I was involved with insurance testing of lifting devices and beams, and I can't now remember

Mind you, it's an even longer time since I did my structures at college

Although I did design some temporary works in the '70s