Scientific American Supplement, No. 799, April 25, 1891Various
Science
Scientific American Supplement, No. 799, April 25, 1891
Various
Science -- Periodicals
She was raised off the rocks by the water rising and compressing the air
in the two foremost holds, assisted by the buoyancy of the engine room
and No. 3 compartments. At high water the bow was afloat, but she was
aground by the stern. When, however, she was taken in tow by three tugs,
she slowly slid down the reef and floated into deep water. One tug was
placed on each bow, and the third was ahead. In this state she was towed
into West Port, a distance of four miles, and there beached on a
sheltered stretch of sand.
The casks performed no part in floating the ship off, but were only
there in case the great pressure of air should cause the escape of some
of it, in which event all the space underneath the lower deck would soon
have been occupied with water instead of air. These casks would then, of
course, have served to displace a large amount of this water, and so
keep her afloat. Luckily the deck did not leak, and the barrels were
thus not instrumental in the raising.
When beached the hatches were taken off, the casks removed, and a false
deck was built about 7 ft. below the lower deck, and about 10 ft. above
the keel. This was used as the bottom of the ship to take her round to
Halifax, and was built in the following manner: A kind of iron platform,
about 2 ft. wide, runs along the sides of the holds in the Ulunda for
strengthening purposes, braced at intervals of 15 ft. by iron beams
across the ship.
On this was built the wooden deck. Beams for this deck were constructed
of three 3 in. planks, and were laid down on the iron platform about 3½
ft. apart, and firmly wedged into the ship's side. On these beams a
layer of 3 in. planks was placed in a fore-and-aft direction and nailed
down; on this were three layers of felt, and on this again more planks
were laid down in the same direction as before.
The whole deck was then carefully calked and the sides made watertight
with Portland cement. This deck only extended to the engine room
bulkhead through the two foremost holds. It was prevented from bursting
up by the pressure on the bottom of it, by means of shores, in the same
manner as the iron deck had been served before. Shores were, therefore,
connecting the three decks--the upper deck, lower deck, and wooden
deck--this being done to equalize the pressure on the _extemporé_ deck
and the two permanent decks, and thus gain additional strength.
Public-domain text, read in full here on John Shaqi.
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