Propeller Math Reality Check

[cyberbadger]

Bart/Mike,

Ok. Ok. I got it.

The Boiler pops off at 200PSI.

I own two candidate engines:
1) A single cylinder simple 2.75 inch bore by 3 inch stroke, slip eccentric reversing running gear, built by John Winn in Abingdon, UK. (It was the engine in 18 ft SL Chimera in the UK)
2) A 1902 Toledo Steam Car simple/single expansion 2 cylinder 3"x4"(both cylinders) with Stephenson reversing gear, rated as sold as 6HP.

I'll do the calculations, but I'm really missing an important variable right now in order to complete them. A hull!

I'm looking for something between 20' and 30'. I don't want anything made new as nice as that would be. My current thought is a used sailboat hull.

-CB

[Lopez Mike]

I'd vote for the twin. To be honest, mostly for the ability to start and reverse without having to give the flywheel a kick. I seem to end up doing a fair amount of close quarters fooling around and a single with slip eccentric seems like it would be a hassle.

With that much pressure you will have more power than you need but you don't have to run it that high.

Mike

[cyberbadger]

I'd vote for the twin. To be honest, mostly for the ability to start and reverse without having to give the flywheel a kick. I seem to end up doing a fair amount of close quarters fooling around and a single with slip eccentric seems like it would be a hassle.

With that much pressure you will have more power than you need but you don't have to run it that high.

Mike

Mike,

You are on the money - but not considering the option that I am....

Why not BOTH!

I'm will be running non condensing, so it's not that difficult to fit to each. Each engine weighs roughly 100lbs.

One powerful engine for reversing and close quarters and manoeuvring.

One for long haul economy.

-CB

[Lopez Mike]

Are you off your meds again? I can barely keep one engine running!!

Mike

[cyberbadger]

Mike,

I like backups, and backups on the backups.

I'm sure you can appreciate that Mike.

On the water it is only you and your launch and what is on board.

2 ways to check the boiler water level. (sight glass and trycocks)
2 ways to get water into the boiler. (at a minimum)

I'm just adding to that...

2 Engines for different purposes.

One boiler to unite them all and in the darkness bind them.

-CB

[DetroiTug]

One powerful engine for reversing and close quarters and manoeuvring.

One for long haul economy.

Being that both engines are simple, there is no economy one over the other to be had. All that any steam engine can do is convert the power created by the boiler in to real work. In the case of the compound or the Uniflow, they will do more work on the less steam compared to a simple.

Switching from one engine to the other would be the same thing as increasing or decreasing the steam flow or throttling.

-Ron

[Lopez Mike]

Well, at any rate, you will stand out in the boat registries. I don't know of any launches set up like that.

For me, space is at a premium and anything that takes up more room gets the stink eye.

Mike

[S. Weaver]

Mr Weaver, what kind of oil do you use? Any additives?

Pin, Bearing & Journal 460 and 220.
http://www.steamenginelube.com/engineoil.htm