The age-herald., 1898-09-10
ADMIRAL CERVERA'S
 SUNKEN CRUISERS

ago de Cuba?" was asked the senior mem- | Der of a prominent New York wrecxing | firm.
 Well, we can do it in several ways" was l the reply. "Yet, there are but two princi- | ples involved in the work. One calls for the
 use of pumps; the other involves the use of pontoons. The pumping method is used
 when the vessel stands above the surface and has suffered but little damage in the
 hull; pontoons are used in deep water, | wl-ere it is possible to send several big ca bles down under the hull to lift it, and | where the rise and fall of the tide is great enough to lend material assistance in the work.
 "A notable instance of the use of the pumping method occurred in the North sea a couple of years ago. The Sodia Sverige, a large steamer, sank just below the sur face Divers first went down and patched up hole which was then in her side. Then they built a great square tube of wood and plunged it down into the water, through one of the hatchways, into which 1t just fitted. It was bolted and cemented to the edges of the hatch so that no water could pass the joint The upper end of the great tube reached above the surface of the wa ter. All the other hatchways and every other opening in the hull of the vessel was boted and cemented. The hull, in fact, was made water-tight. No water could get in and none could get out. A small rotary pump designed by de Laval, the Swedish inventor, was brought into operation. pipe from this pump was thrust down through the great wooden tube, the only 4R thn htlll the pump was set going. In five hours all the water inside the hull was pumped out and the air which rushed in to take us place caused the steamer to rise to the sur face. Of course the great wooden tupe rose with her, and stuck up like a square smokestack But that was soon knocked away and the vessel went into Christina under her own steam. This method IS known as 'stankng'-a contraction of the word staunch.
 "It is sometimes possible to build water tight chamber inside the wreck and by ex- hausting the air within give to the hulk buoyancy which it would not have other wise and which would raise the wreck to depth at which repairing could go on more advantageously. The sunken steamers Aus tria and Utopia were saved by bottling one of these water-tight compartments to the decks. The buoyancy imparted by this chamber was great enough to lift the ships from the bottom and allow them to be lowed into shoal water, where lighters took up the load and held the vessels where they could be temporarily repaired, preparatory to going to dry dock. have heard it stated that Hobson would follow this method somewhat by employing air bags, which
 would be blown up by compressed air in- side the hull of the Colon and other ves- sels.
 Building platform under a vessel and raising the structure with the vessel upon | it is resorted to when the skin of the ship is very much damaged. The Vizcaya would have to be lifted in this way to pre- vent her falling apart. It was used after a curious accident, which happened to
 vessel in Boston harbor a short time ago.
 You know the harbor is very narrow in
 places, and in one spot very long steamer
 went ashore. Her pilot missed his calcula-
 tion, l suppose, but at any rate she stuck
 her nose against one bank and the current
 sweeping her around jammed her astern
 against the opposite shore She stuck fast.
 
 high and dry in the form of bridge ex-
 tending from bank to bank. The weight of
 her cargo then caused her to sag in the
 middle, as she had no water to support
 her, and it was feared that she would
 break in two. At first it was proposed to blow her up, as she blocked navigation,
 but by means of a platform having water tight compartments, she was floated into IL, merely an arrangement of timbers hang ing between two great floating boxes or platforms. They were placed under the vessel at low tide one pontoon on each side of her. When the tide rose 1t lifted the water-tight compartments, which came upon each side of the steamer and raised her out of her trying position.
 Hobson will probably use pontoons in his operations on the Colon. She was not
 much injured by the American guns. Her sinking was caused mostly if not entirely by the opening of her vent holes. I believe she ran well up on the beach, but after ward listed and fell into deeper water. It will therefore, be matter of compara- lively small moment to place her hull in a condition so that she can be pumped out. It could be done by sinking a great tube, cementing 1t to a water-tight compart- ment and by pumping out the water cause the boat to float herself. It could be done by building water-tight compartments in-
 side of her or by repairing and pumping the water from those which naturally ex- isted on board of her. It might be done with those air bags we hear so much of, but it will probably be done with the "cam- els" as we call the pontoons Perhaps it
 will be done with several of these methods combined.
 The pontoons are ponderous affairs.
 They look like great oblong, unwiedy
 hulks. but are capable of being manipula- ted as handily as a steam yacht, They are simply immense floating boxes divided into
 a number of airtight compartments. Any
 one of these compartments may be f1oated
 at will so that the pontoon can be made to
 list heavily in any direction, an action
 which is most useful at times when a
 stress must be had in any particular di-
 rection. Some of the pontoons have a
 thousand tons displacement. Several of
 them in line, with their combined power,
 can lift an enormous weight. Of course,
 1t is the power of the tide that really does
 it all.
 "When sunken wreck is to be raised,
 the pontoons are foated directly over it,