Wednesday, November 9, 2011


Second of two CAT C-18 engines with Twin Disc
marine gear, ready to
be lowered through a main deck opening
Bay Ship Building, Sturgeon Bay, Wisconsin -

Catching up with some of the photos I took last week of the Robert Noble repowering project, I've posted several of them here.  Since that date, much has been accomplished.

Both engines have been set on engine bed framing and aligned, and by now a hard resin known as Chock-Fast has likely been poured beneath the mounting plates.  Piping of cooling lines has begun.   Keel coolers have been installed, from the underside of the hull.   The new props were mounted on reinstalled shafts and secured with large brass nuts.  Rudders that were slightly enlarged were reattached.  The hull exterior was spot-blasted where needed, and painting over those areas was completed.

As of today, nearly all work has been completed outside the hull.   In the near future, the ferry will be floated from the dry dock.  Then, remaining interior work will be done while moored to the pier.  A solid two-to-three weeks of piping, wiring (including gauge panels in the PH), insulating, painting and dockside testing are necessary before the ferry will be ready for a sea trial.

Rich Ellefson has monitored work there since the ferry went into dry dock, Monday October 17, and has spent long hours on board each day following up on details.  Results, though far from complete, already indicate wise choices in use of the limited engine room space.   Equipment placement, wiring run locations, and essential piping that can avoid traffic areas is considered carefully for later ease of service and maintenance.   Regulation governing small passenger vessel design adds to the volume of valves and wiring, for example, but the engines themselves are more compact than the engines they replaced.

Starting battery banks, separate and distinct for each engine, were shifted to a seldom-used alcove, one example of how sensible redesign can save space in the more frequented walkways.  Main engine exhaust lines, essential to carrying away hot emissions, grew from 6" diameter pipe to 8" pipe, are another challenge because they will hang directly above the shaft alleys, limiting side-to-side movement for service in the engine room.   However, on the port side which is near the engine room entrance, round pipe will be replaced by a flattened, rectangular tube, so that crew members can more easily duck  beneath.  

As more equipment is piped and wired, remaining open spaces will gradually close in, but the intended result is to maintain sufficient room to move and to service the equipment that may be superior to the original layout.

Following are more photos that show progress as of 11/1/11, which was the approximate starting point for putting the engine room back together.    -  Dick Purinton

Rich Ellefson and Bay Ship machinist discuss
cooling water connections.
Engine room, starboard side looking aft:  new waste holding tank
is outboard, at left; bulkhead plating with round access hatch 

to steering room was cut, then flipped 180 degrees and reinstalled to 
avoid new exhaust run.  Exhaust pipe will penetrate 
bulkhead to left of stanchion shown in foreground.
Starboard rudder, foreground, with additional surface 
added to trailing edge, hangs from chain fall, ready
to be reinstalled.  New starboard prop is
already mounted and secured to shaft.


Bill Tobey said...

Thanks yet again, Dick, for keeping us up to date on the Robert Noble's progress (as well as all of your other topics). I meant to comment earlier that the aerial fire truck probably paid for itself at the West Harbor Resort fire.

But back to this topic, I'm not a ship expert but I was surprised to see the ribs on the rudder's side. It would seem that they'd induce drag, especially since they're in the heart of the propulsion stream. Is there some simple explanation you can offer? I've speculated to myself that maybe what we're seeing is the skeleton of the starboard rudder and that there's a smooth "skin" that goes over it.

Richard Purinton said...

Bill - Thanks for your comments. I think many here on Washington Island, including firemen, believe this used, former Liberty Grove aerial truck was well worth the money spent. The entire sum (around $45,000) was raised through donations in a few month's time late last fall. *** As for the Robert Noble rudders, you're correct in that the drag is increased with those exposed horizontal stiffners. To put a skin over frames would increase weight somewhat, and fabrication and welding time, and maybe the designer thought that hull speed through water was sufficiently low anyway, and not a great enough concern to require a smooth outer cover?
Most likely, prior examples in our fleet were observed, such as the Eyrarbakki's and Voyageur's rudders. I believe each ferry built after the Robert Noble has also had a flat plate for a rudder with exposed strengthening bars on either side. The C.G. Richter, as I recall, did have a molded, or "hollow," rudder with a drain plug on the bottom. - Dick

Bill Tobey said...

Color me laughing at myself, Dick. I didn't study the picture and your text, which included "additional surface added to trailing edge", well enough to deduce that the rudder is hanging roughly 90ยบ in pitch from it's installed orientation which puts the stiffeners parallel to the water flow. Thank you!