Thursday, 18 August 2011

Stern gear installation and fuel tank

Above is the stern tube welded into the hull. It is threaded internally to accept a bronze bushing bored to a slightly larger diameter than the prop shaft.
Click on the photo to enlarge it and the threaded internal bore into which the bush is screwed can be seen.
The bush is sealed in place but may be removed for replacement if required eventually after several years wear.

This is the internal view of the stern tube. Forward of this is a plate drilled to carry the stuffing box which is effectively a gland through which the 2" diameter propeller shaft exits the hull. The stuffing box contains a greased rope gasket wrapped round the prop shaft and compressed to form a tight seal which keeps the water out.
A grease injection system (the stern greaser) will be added later.

Further forward of  the stern bearing is this plate which is drilled ready to accept the front/inboard bearing of the 5 ft long propshaft.( Forward of this bearing the propshaft will terminate at a flange which will couple to a cardan shaft with universal joints at each end. The cardan shaft will continue forward to the gearbox.)
 This plate is made from 12mm baseplate offcut.
The top of the plate has a flat surface 16 1/4" above the baseplate which will carry the floor in the back cabin.

Turning 180 degrees from the front bearing and now looking forward the fuel tank can be seen.
The cardan shaft will pass through the "notch" in the fuel tank and couple up to the gearbox seen beyond.

The 100 gallon fuel tank, which has been pressure tested to ensure it's integrity has these two removable plates installed to give access to each side of the tank should cleaning, gauge fitting or other modificaton be required. The main feed tappings are for the engine and the Kabola diesel fired central heating boiler.
A breather and balance pipe beween the two upper tank halves will be installed.

The tapping for the diesel filler is on the port side under the back cabin floor. It is angled forward to allow the fuel filler to be forward of a welded joint in the gunnel (good practice) and adjacent to the engine room where a valve will be installed to allow tank isolation. The valve is intended to stop fuel theft.

1 comment:

  1. Is fuel theft a problem there n the UK ?

    So far it is not a problem here.
    I carry 630 Gallons in a 46' boat

    Bill Kelleher
    Toledo, Ohio