represent a light buoy made by the Pintsch's
Patent Lighting Company for the river Humber. The chief dimensions of the
buoy are given in the engraving, which also shows that the gas holder is
placed within the boat in such a way as to be protected from blows likely
to cause any leakage. The buoy has a special form to meet its requirements
as a lightship, and the conditions of its employment is the fast tidal
current of the river. It was designed by Mr. C. Berthon, of Westminster,
and is intended to carry a six months' supply of gas, the burner,
regulator, and lamp being on the well known Pintsch system. The hull is
formed of 3/8 inch plate, 24 feet 3 inches total length, and 9 feet beam
at the line of flotation. The laps of the plates are 4 inches wide, and
riveted with 3/4 inch rivets, spaced 2-1/4 inch apart center to center.
The keel and stem are both in one piece, as shown, and to this the
garboard strake is to be fastened. The bilge pieces are riveted on to the
bilge, and made of 9 inches by 4-1/2 inches by 9/16 inch T-iron. A wooden
fender, 4 inches by 4 inches wood, is fitted on both sides of hull,
running from stern to stern, by 3 inches by 3-1/2 inches by 7/16 inch
L-iron top and bottom with the sheer as shown. The hull from water line
falls in as shown, so as to describe at midships an arc of 4 feet 6
inches, and a circular deck of 1/8 inch plate is riveted on the hull.
There are two man-holes, each 16 inches diameter in the clear, placed in
end plates of the circular deck as shown, and provided with covers 3/8
inch thick, secured by twenty screws 3/4 inch diameter. The edge of each
manhole is stiffened by a welded iron ring. The surface of the mooring
link that comes in contact with the shackle and mooring chain is steeled.
The gas holder rests upon a plate bent up on each side, and riveted to the
keelson, and is prevented from rolling by four gusset plates, with two
short pieces of angle iron riveted thereto at the ends and coming in
contact with the holder, and at the ends by angular plates, and angle iron
riveted on each side and riveted to the keelson. The superstructure
consists of four legs of angle iron 2-1/2 inches by 2-1/2 inches by 5/16
inch, the upper ends of the legs being attached to a square flanged plate
for supporting the lighting apparatus. Four wooden battens of pitch pine,
4 inches by 1-1/2 inches, and bolted on to each cant of the angle iron
superstructure, with 7/8 inch galvanized iron bolts