"So how will that engine work anyway?"

A common question, and up until now, I had yet to find a compelling graphic aside from some video links that show marine compounds in operation.  But wonder no more ... colleague Mr Anderson sent me a link that contains a graphic of an Olympic class engine.  The White Star Line Memorial Foundation has produced this graphic:

[Throw the reverse lever over and crack the throttle ...]

Iona's engine has a high pressure and low pressure cylinder, but no intermediate cylinders.

Some holiday work

Work has slowed a little here in the dead of winter, though tonight we are experiencing a relative heat wave of 24F (-4C) compared to recent temperatures.

Christmas was duly celebrated by all at the Works ...

Here, Quinx is deep in her cups, polishing off the last of the eggnog.

I took advantage of a relatively mild day to begin laying the decking.  The sub-deck was warmed with heat lamps to help kick the epoxy.  It responded admirably.  I was surprised about the willingness of the teak to be bent laterally through as tight a curve as a 60-inch radius.  In this shot, the clamps have been removed at the sweep of the bow.  One can see the faint marks for the following planks, where they will rest against the king plank.

Meanwhile, the heated shop at work allows for continued tack up of the smoke box:

An Early Christmas Gift ...

... arrived the other day.  Teak decking from Boulter Plywood.  Boulter has provided most of the wood for Iona, so this is also a plug for Chris and the gang - thank you!

The first box laid out on the horses:

Carefully opened ...

Ahh ... vertical grain quarter-sawn 1.75" x 0.5" Burmese teak.  It will be planed to a thinner dimension before setting on the sub-deck.

A morale poster also showed up in the Works.  Best Beloved is puzzling over its significance ...

The Smokebox

The boiler was on hold for a while as I pursued other things, as seen in recent posts.  The smokebox design then finally drafted by Mr Anderson, and the laser-cut pieces arrived, demanding attention and fabrication.

Below is the incomplete furnace frame with the partial smokebox frame set in place to adjust fit.  A hydraulic press punched the box frames for the door dog bolts.  I'm tacking the pieces together by stick, later to be seal-welded with 0.023 MIG wire.  The furnace and ash frames will be fitted with protruding sealing lips, and custom doors made with the appropriate drafting devices.  To be fitting and welding again is a great joy.

And yes, the boiler is on end inside the roof sheet of a Belpaire boiler, standing on its nose. A totally unrelated railway project ...

The Steering Gear

One of the tasks that requires completion before the hull is decked is the fitting of the steering gear.  Said gear runs the range from the practical - clothesline run through zinc-plated blocks - to the sublime - sailboat systems manufactured by Edson Marine.  I admit I appreciate well-engineered systems.  Edson had me as soon as I received their catalog.  The heavy bronze quadrants; the exquisite sheaves - what could I do?  I had to throw money at them ...

After mounting the rudder, I came up with a system of blocks to act on the rudder.  A port-side helm station was always the idea.  The problem than became how to run the cables to the sheaves and the rudder quadrant.  This first picture is the helm station, with the steering chain and cables emerging from its aft side.

A standard Edson bulkhead gear will mount on the box, with the proper fine wood and all.  The standard taper didn't fit an antique wheel I received from Greenwich, UK, so we had to take the thing apart and machine the shaft.  (I'm still not sure whether or not I'll use the brake, though it is set up for it.)  The cables then lead aft to No. Four frame, in the foreground here, where two standard four-inch idler sheaves were set up to maintain the cable's suspension around the corner.

Here's another picture of the No. Four sheave mount:

Swapping orientation of the cables was then in order, as seen above, so that the bow swings in the proper direction with the wheel.  Piercing No. Five bulkhead got me into the rudder compartment proper where I could thread the blocks which act upon the quadrant.  Here's a shot of the stern compartment with the cables under temporary tension in order to see how the whole rig works:

It was pleasing to manipulate the chain at the helm box and watch the whole thing silently swing through its paces, without slop.  After determining that things would work, I then disassembled the cabling and idlers to seal the bulkheads where they were bored and to apply the correct fasteners.  Jibes are coming about "a rig that will sail around the Horn," etc., but I don't believe I'll be using the emergency tiller any time soon.

It will soon be time to finish decking ...

A Rudder for Iona

Iona's rudder arrived from the foundry.  So it was off to get the keyway machined (courtesy of Mr. Anderson), and then back in the shop to be balanced, dressed and have a hole bored so the prop shaft can come out with the rudder hard over.

Next was the trial installation.  The hull was to be pivoted on its forward jack stands, so I knocked out the keel blocks forward of the stands and put the lift on bulkhead No. 5.  Here we arrive at our final height, measured by the rule in the shaft hole, with Quinx, the shop cat supervising as usual ...

With the stern hanging on the lift, the rudder is started home.

Gauging the progress of the shaft as the hull slowly descends.  Quinx is checking the credentials of the photographer, as no unauthorized personnel - by her definition - are allowed in The Works.

 The hull is almost on the stern keelblocks and stands.

The hull is home.  I've not totally settled on the means of rudder suspension.  A bracket with bronze collar will probably be on the underside of the king plank support, above the quadrant.  The shaft extends a little up through the king plank for the possibility of an emergency tiller, should the steering gear fail.  I'll figure on some kind of fancy bronze deck cover for it.

After head scratching and fabricating, there will be future lifts for the final installation.  That's when the packing gland, seen sitting to the right of the slings, will go in.

Looks like the local graffiti artists have tagged the hull again.  Not a bad sentiment on the kind of project that can tend to strain the checkbook and marital bonds ...  Photos courtesy of said graffiti artist - thanks, babe.

Engine Beds - Part II

Notwithstanding all of the hullabaloo surrounding the prop, it was time to get the engine beds in permanently and the position of the engine defined, since so many other things - piping, for one - depend on the fixed centrality of the engine.  So out came the shaft hubs, recently machined, and the engine lift again, and all was swung inboard to begin the alignment process.

This photo was taken when things were about dialed in, however it shows the many considerations in play:  The engine is in its position fore and aft.  Though the floors are fairly true to the gunwales, I nonetheless strung a straight edge* across to make sure that the engine would be perfectly perpendicular to the plane of the waterline.  I would see where the engine was sitting with respect to the shaft hub, lift up the engine a piece, knock the beds out and plane them to where I thought they should be, re-install them, measure and fuss, lift the engine a bit, knock out the beds, etc.  *(Purists will worry about my use of a treated piece of junk pine for a straight edge, but I couldn't find my prized Doug fir batten ... One grabs what one can in situations like this.)

Finally, I had things to around 0.005" on the tips of plastic epoxy spatulas, confident that permanent shimming could be accomplished from there.  Here's a close up of the hubs all but dialed in - bright engine hub forward and gray shaft hub aft -  with the spatulas serving a nobler task than normal.  The hubs by the way, are off the shelf, Buck-Algonquin ductile iron, cast within a couple miles of our house.  The shaft hub remains stock while the engine hub has been extensive modified to clear eccentrics, retaining nuts, etc.

To the port of the engine, forward of the aft floor behind the low pressure column is where the crosshead-driven pumps will sit on their bronze bedplate.  This bedplate has to be let into the beds its thickness.  So, the lift whisked the engine back to the bench, out came the beds for the last time and out came the chisels.  With the beds then finish dressed, I epoxied them into place.  The beds themselves were left unfinished except where the bonds on the tenons and and floor shelves were made.  Later, I'll treat them with raw linseed oil and turpentine - love that old boat smell!

Here is a shot with the engine back on the bench and its hub coming off.

The hubs, bearing caps (here, in red) and other items will go out to the powder-coating shop for their final finish.  One can see the pump links, and other items, namely the exposed low-pressure valve seat on the yet unfinished engine.