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Taranaki Herald, Volume LVIII, Issue 14245, 25 June 1910, Page 1 (Supplement)

Few ratepayers in the New Plymouth Harbour rating area have any

idea of the dimensions and capacity of the twin-screw stern-wcll-bucket

and suction-hopper dredger, now on the way out from Scotland to the order of the New Plymouth Harbour Board. Our thanks arc due to the makers for two very excellent views of the dredger, taken when com-

pleted. Messrs. Fleming and Ferguson, Ltd., engineers and shipbuilders, Paisley, Scotland, were the successful tenderers, their price being £33,000. The tender was accepted on the 24th of April last year. The contract provided for delivery at New Plymouth Breakwater within ten months of the acceptance of tender under a penalty of £2O per day. Commencement of the work was somewhat delayed, and it was not until the 14th of January of this year that the ship was launched.

After all necessary fittings were added, the dredger was tested for sand-pump dredging at Fleetwood, and on the Clyde at a depth of about 40ft for bucket dredging. The

vessel also underwent her speed

trials on the measured mile, slightly exceeding the contract speed of eight knots per hour. She was then docked, dismantled, and fitted with spars, sails, etc., and generally prepared for her long voyage to Now Zealand. The vessel had to be measured by the Board of Trade and the

necessary pass taken out from the Registrar of Shipping, and a Suez Canal certificate obtained, to enable the ship to proceed to her destination. A properly-qualified captain, officers, engineers, and crew had to be engaged, and the ship properly provisioned. On the 24th of March the “ Paritutu ” sailed from the Cylde, via Colombo, Albany, and Wellington.

Built under Lloyd’s special survey and classed Al hopper dredger, the very best workmanship and material have been used throughout. Ratepayers will be interested to read that the builders contract to deliver at New Plymouth, and to work and maintain the dredge in a perfect and

complete state of repair for 72 working clays after commencement of regular dredging work at New Plymouth. At the expiry of this date, the final payment of 10 per cent, on the contract price will be made. The following details of her capacity will show how great an improvement she is on the “Thomas King,” which

has done such good service for so many years. The dredging gear is to be mounted on a self-propelling seagoing steam hopper barge of mild steel, the capacity of the hopper to be not less than 8,000 cubic feet measured to the level of the main dock, and when fully loaded to comply with the following conditions : Length between perpendiculars, 180 feet. Length overall, hull, about 185 feet. Moulded breadth, 34 feet. Depth, 13 feet. Her mean draft, with 400 tons in hopper, 50 tons of bunker coal, and 20 tons of water in her boiler feed tanks, is 10 feet 3 inches. Her speed, as already stated, is eight knots, and her dredging depth 40 feet. Her propelling power consists of two sets of triple expansion sur-

face condensing engines, each having cylinders of llin., 18in., and 30in. dianictcr, capable of developing 600 1.11. P. These will be arranged for driving the twin screws, one engine being also arranged to drive the sand pump, and the other the bucket chain, all the necessary disengaging clutches being provided.

The vessel is fitted with a sandpump, the diameter of the suction nozzle being 20 inches, and fitted with a rotary cutter with blades of manganese steel, and driven at the rate of 20 revolutions per minute, tor increasing the delivery of sand and cutting into hard ground. The pump and engines are amply sufficient to fill 400 tons of fine loose sand into the hopper in half an hour. The sand-pump will be so arranged as to come in-board above deck when not required for dredging. There will also be an indicator in the engineroom, showing the depth of the suction pipe when at work. For dredging in mud a bucket ladder with chains of buckets working in a stern-well in the centre arc fitted. The buckets arc about 8i cubic feet capacity, and 37 in number, and geared so that the speed of about 10 buckets per minute may be main-

tained. Twelve pairs of strong caststeel rock pins will also be provided for insertion in the bucket chains, each fitted with a renewable point of manganese steel, suitable for cutting into hard ground. The buckets are capable of loading into the hopper 300 tons of soft clay per hour. Spare parts will include 12 buckets corn-

plete, 2 picks complete, and 36 pick points. The accommodation for the officers and crew is very complete. The cabins are so arranged and fitted up as to give four separate apartments for officers and engineers, and a mess-room with companion and skylight combined. The cabins will be upholstered, and fitted with bed, drawers, lockers, and wash basins, and all necessary fittings. The crew’s space will have 10 berths and the same number of lockers, mess table, and pine seats. A galley is fitted in a steel house on deck, containing a 3ft. cooking range, 10gallon boiler, and all necessary cooking utensils. The contract price includes all necessary plate, cutlery, and crockery, even including dessert knives and forks. A suitable navigating bridge, with all necessary wrought iron stanchions and rails,

is provided, and on the bridge deck a suitable combined steam and hand steering gear is provided, together with a complete set of navigating instruments. The electric light generating plant provides for a continuous output of 5 K.W. at 100 volts, providing three 32 c.p., twenty-two 16 c.p.,-and three 10 amp. arc lamps.

Included in these are a masthead light and two side-lights for navigating. purposes. The vessel itself is divided by bulkheads into watertight compartments. The bunkers are capable of carrying 140 tons of coal. The deck outfit and furnish-

ings, which are very complete, include three boats, one a lifeboat 16 feet long, a dinghy 12 feet, and an anchor boat 19 feet by 6 feet 3 inches by 2 feet 6 inches. Three stockless anchors of 16jcwt, including one spare one, and four ordinary anchors of Scwt each, are also provided. Two powerful steam mooring winches are fitted at the stern of the vessel, and a powerful steam windlass is also fitted at the bow. The evaporator is capable of yielding 4 tons of fresh water in 24 hours. The vessel and fittings are most complete throughout, and everything seems to have been provided for, even to an ink-

stand, box of pens, and 6lb of stationery. Upon arrival at Wellington the dredger will be placed on the patent slip, and cleaned and painted with anti-fouling composition, all voyage fittings removed, and the vessel fitted out for dredging, and then delivered in working order at New Plymouth.

The contract price includes all expense of bringing vessel to New Zealand, cost of docking at Wellington, and the working and maintenance at New Plymouth for a period of 72 working days after it has commenced its regular dredging work at New Plymouth, and at the expiration of the maintenance term it shall be left in a perfect state of repair. Upon completion of the vessel, a finished model was to be supplied to the Board. In order to give an idea of the work required to be done by the “ Paritutu,” and of her working capacity, as compared with the “ Thomas King,” we may point out that the latter in the last ten years has dredged an average of about 125,000 cubic yards of sand each year, and has thus succeeded in practically maintaining the general depth of the harbour, without allowing the sand to silt up the harbour on the one hand and without appreciably increasing the depth on the other. The little vessel has done really wonderful work at a cheap rate, but the time has come when the depth of the harbour must be increased, and the hard bottom be dug out as well as the loose sand removed.

The sand-pumping capacity of the “ Paritutu ” is, as stated above, 400 tons per half-hour, and assuming that it takes another half-hour to

discharge and moor the vessel, and that she works ten hours a day for 250 days in the year, we get a capacity of a million tons a year, or eight times as much as the “ Thomas King” has been doing in the last ten years.