Monotube Javelin

[fredrosse]

O'Day Javelin was converted to an all electric launch several years ago, but not used for over 10 years, since Margaret S was completed in 2010. A 14 x 17 three bladed prop had been fitted to this hull in place of the original centerboard well.

Yesterday we launched this 14 ft boat with a new oil fired monotube steam generator, for a preliminary shakedown cruise. Steam is raised quickly, about 30 seconds for steam pressure to start building up, about 2 minutes to reach 145 PSIG (10 Barg). Poppet Valve Uniflow engine worked well, driving the boat at 5-6 knots. Engine vibration is a problem at around 700 RPM. I may need to change gearing to get around 1000 RPM, I know the engine is settled down at that speed.

A few initial problems that will be relatively easy to fix, the motor driven feedwater pump kept unloading, so we had to use the hand pump. No exhaust piping on the engine, and no tall stack on the steam generator, so Mark and I suffered with steam, copious amounts of heat/humidity, as well as oil burner fumes. That will all be corrected before next running.

[DetroiTug]

Congrats on your new build. Sounds like you had good success for a first run, there's always issues to work out.

When I look back at the first run of the tug, there have been a lot of changes since then. We were fighting to hold 30 psi. Taking on feedwater we may as well have dropped anchor with no economizer

Ron

[cyberbadger]

I definitely appreciate that you have made a steam plant light enough to fit in a such a short boat. Serious weight constraints were met to pull it off.

Vey impressive.

-CB

[RNoe]

Impressive project! Another sailboat converted to steam.
Welcome to my club.
I will be watching.
RussN

[fredrosse]

The Javelin hull is designed as a small day-sailer, and the sail force tends to push the bow down, and forward. The forward part of the hull is rather full-bodied to provide enough buoyancy when the sail is vigorously pushing the hull down and forward. This type of hull design is therefore somewhat forgiving to my locating a rather large and heavy steam plant so far forward.

The original empty sailboat total weight is listed as 585 pounds (265 kg), and three passengers at 175 pounds each, original total displacement was about 1100 pounds. The steel centerboard was removed, but the the steam plant weight is about 600 pounds. Add to that the two group 27 lead acid batteries in the stern, needed to run the oil burner and feedwater pump, plus a couple of passengers, we probably have about 500 pounds (227 kg) added to the original hull "as designed" total running displacement. That ends up adding about 1-3/4 inches draft (44mm), and that matches fairly well with what I see compared to the boat's original waterline paint.


Edit 19Aug 2021
Just completed actual weight measure with pneumatic cylinders and pressure gauges on the lifting hoists. 1300 pounds (590kg) with about 50 pounds of fuel oil onboard, no passengers. Therefore running total displacement on videos is 1300 + 170 = 1470 pounds (667kg), or 0.656 long tons

[fredrosse]

For those who may be interested, there are some technical details about this monotube steam plant are located in another thread on this forum, under the "Engines and Boilers" section: "What water speed do you work with in monotube boilers?"

Very crowded arrangement under the forward deck, containing Generating Coil, 120VAC Oil Burner, 12VDC-120VAC inverter, fuel supply and return hose, with large filter, letdown heat exchanger coil, (40 feet of tubing), burner pressure switch, letdown overboard discharge valves, separator thermodynamic steam trap to backup letdown flow, feedwater flow lines,one direct into generating coil, other thru the letdown heat exchanger, stainless flex connection from generating coil to separator pressure vessel. Small electric diaphragm pump, with manifold allowing lake water boost into feedwater pumps, or alternately can be valved as a bulge pump. Crowded but still easier to work on than the engine compartment of a modern automobile.

Just aft of the deck, separator vessel with relief valve and several other connections, uniflow engine, with roller chain drive to propeller shaft, motor driven feedwater pump, hand feedwater pump, stainless flex connection to engine, steam isolation valve, engine throttle valve.

[fredrosse]

Lake Noximixon Steamboat Meet 14 Aug 2021. Had the new boat underway, a nearby steamboater took some moving pictures, on facebook "fredrosse". Everything worked as designed, but still a little rough around the edges.

Technical details for first running: 125 PSG (8.6 Barg) steam, 62kW Firing Rate, making 6 knots with a 350cc Uniflow engine at 700 RPM, prop at 525 RPM.

Design will eventually run at 250 PSIG (17.2 Barg), 125kW Firing Rate, making a little over 10 knots with a 1000cc three cylinder engine at 1000RPM engine & Prop. To quote from a relatively famous movie: "You're gonna need a bigger boat"

[TahoeSteam]

Would love to see videos Fred.

Do you have the link?

[fredrosse]

https://www.facebook.com/fred.rosse.5/p ... &ref=notif

Does this work??

[dampfspieler]

Hi Fred,

looks and sounds great (seen on my facebook-acount). The video is only visible at FACEBOOK. If you want to share in a forum you should host it at youtube or vimeo and mark it as "not listed".

Best Dietrich