INDUSTRIAL ASSOCIATION.

Dominion, Volume 3, Issue 843, 15 June 1910, Page 6

INDUSTRIAL ASSOCIATION.

A meeting of the General Committee of tho Wellington Industrial Association was held last night. The president, Mr. E. Bnll, was in tho chair, and thero were about a "dozen members present. The Hon. J. A. Millar, Minister for Labour, wrote stating that a Hill dealing; with exhibitions had been prepared for submission to Parliament this session. Provision was made that any exemptions from the regulations of the 'Shops and Otlices and other Acts administered by tho , Labour Department might ho made by Or-der-in-Council from time to time. It was decided to co-operate with tho City Council in welcoming the new Governor. The secretary (Mr. 11. ■!'. Allen) road a report on industries inspected by him dur- i ing a recent visit to Auckland. A. vote of thanks was passed to .Air. Allen. j A discussion on the Labour Depart- i mcnl's demands for information for cen- i sus purposes is published in another | column. , Reference was made to the possibility of i the Government subsidising a Vancouver , service, and ■ a resolution was unani- , niously agreed to urging that in the , event of such a service being adopted , Wellington should bo made the port of j cali i

A NEW METHOD. « • CONCRETE WORK AT THE DOCK. MIXTURE SHOT THROUGH TUBES. About a fortnight ago or more an account was given in these columns of a v new method of depositing concrete at r : the dock site, where there is a depth of i about 45ft. of water. All Wellington 1 knows of the repeated experiments with i a view of getting concrete to set on the ; bottom of the harbour at the dock site, the trouble being a softening of the. i material, called "laitance" (which robs I the concrete of its virtue by the effect on 'the cement). The last experiment ; was the lowering of the concrete in a I continuous stream to the bottom of the i harbour by means of a twelve-inch steel < tube. Several cubic yards of concrete I were laid in this maimer, and inspection : since has shown the new method to be I the one wanted. The concrete, it is . stated, has solidified splendidly, and a i flooring of such material would be quite impervious to the water pressure from ; underneath. Naturally the solution of : the difficulty is hailed with a great deal j of satisfaction by all concerned ' and it is now considered likely | that a complete plant will be or- '. dered within a few days for the deposit- '. ing of the concrete by tube. An import- ' ant factor in the new process is that the concrete must be mixed on the ■ spot — no time must be allowed for any. settling to take place. This was done in the recent experiment by mixing the concrete on a staging above tho "shout/" so that no time could bo -given for the henvier ingredients to sink to the bottom. The tube method of depositing concrete in deep water was discovered in the English "Engineering News," of March 17. This contained an illustrated article giving full particulars of the Detroit Rivet tunnel works in connection with which 100,0110 cubic yards of concrete had to be laid at a depth of 70 feet. In this work an enormous punt was used, on which were erected hoppers, mixers, and tubesall complete. These were so arranged as to entail a minimum of labour, the power from tlie boilers driving the cranes, hoists, and other mechanical gear. If, as anticipated, tho Harbour Board is satisfied witii the results of the latest experiment, and the contractors (Messrs. John M'lean and Sons) are afforded facilities for continuing the contract on thess lines, a somewhat similar'method of laying down the concrete floor will be adopted. Instead, however, of using punts, it is pro- \ posed to erect a \Aattou\\, \ • which will lake, in the full breadth of ' the dock, and this will be fitted with an ; eight-tube plant so that a complete sec- ■ tion of about 12 feet—the full breadth— ! can be laid at the one time. It is cstir \ mated that when running properly a scci tion could be laid in a day. 'Such a . plant would require four sets" of hoppers ! and mixers, and a mechanical hoist for , each of the eight tubes. The action- of • the plant is simple. The gravel and sand s are put into the hopper (by crane) and . through a lower opening Hie cement and 1 wnter are added. After it is thoroughly [ .churned it is led through a tube to the . hoist-well, at the bottom of which is a ( box. When filled with concrete, the box c is hoisted up to a point the height of the . mouth of the tube, into which it ejects , its contents. Tho boxes are filled and , hoisted so rapidly, that a continuous s How of concrete down the tube is assured. r It ,is estimated' that an eight-tube plant . could be worked by from'3o to 35 men , It is understood that the Harbour . Board will discuss dock business at the , meeting to be held on Friday evening.