MINE SWEEPING.

Taihape Daily Times, 26 May 1919, Page 6

MINE SWEEPING.

OFF NEW ZEALAND COAST

THE OPERATIONS DESCRIBED

WELLINGTON, May 23

As the work of mine sweeping off the coasts of New Zealand has been completed for the present, your correspondent obtained from Captain Hall Thompson (Naval Adviser) interesting details regarding its scope. Captain Hall Thampson expressed appreciation of the services of the crews of the two trawlers employed, who were taken over with their vessels, the Nora Ni'v-

cn and Simplon, They had no know-

ledge of their dangerous task, but they swept two mines efficiently. There was mo accident due to enemy mines, but unfortunately one man was lost o\ elboard from the Simplon during a gale and another had to undergo amputation of one foot as the result of an accident in port.

The trawlers swept up a number of mines. The total accounted for, including those exploded on beaches, being 48 out of 60 laid by the enemy. Some “ratings ” were placed on trawlers, but these men had no practical experience of mine sweeping, as this duty only arises during war-time work They had to commence quite without knowledge where mines were laid, except a comparison of plans of suspected minefields, but information supplied by Germans after the armistice show T s that the naval officials made a very accurate guess that their prohibited areas completely covered the danger ports. “When we got the German information,” remarked Captain Hall Thompson, “it was practically word for word with mhat was plotted out, showing that the nmie sweepers did their work efficiently. Operations were commenced simply on the assumption that there was a minefield somewhere. Exploratory sweeps showed there were two.”

One line of mines, eighteen miles in extent, ran in a north-westerly direction from Cape Hooper, off the North Cape, which 'would intercept the courses of vessels coming either from the westward, o r from Three Kings to round the North Cape, and the danger zone fixed directed to keep outside the hundred fathom line, which took vessels thirty miles clear of North Capo.

The second minefield covered a line of approximately 25 miles long off Cape Farewell light, to intercept ships

running up the west coast into Cook

Strait, or coming from Sydney or Melbourne. In this case, too, the di-

reetions from the Naval authorities took ships clear of the danger. The method operating was to make exploratory sweeps until more than one mine had been discovered, when the line of direction could be plotted and followed up. Both minefields wore exposed to bad weather, which considerably increased the difficulties cf work, and in one instance the working off Cape Farewell had to shelter for a fortnight. These fields wore most difficult to clear, as the mines were laid in deep water, and there was no chance of bottom-sweeping, as can he carried out in shallow fields off the English coast. It was possible to w r ork with eight trawlers abreast, but this was out of the question.

The New Zealand naval authorities have complete scale drawings of the mines. It is one good point in favour of the Germans that they were de

signed in accordance with iurernatlon al law, so as to become harmless or breaking loose from their moorings but unfortunately, although gear • war fitted for disconnecting the firing ap -

paratus from a charge of 2901 b. explosive in a mine, ; t easily got out • >f. order by rusting, and was not effect-

A mine was fired by contact with one of five horns fitted around the These wore made of lead, and Fitted within the leaded horn was a small tube of acid, which was cracked on contact and allowed. its contents to saturate a small electric battery, thus creating a current and instantaneously exploding the mine. Each horn was fitted whh this system of electrical firing. The whaling steamer Hananui was employed for the final sw;;3d, and the Admiralty is now sending out to Hew Zealand two mime-sweeping sloops specially built for this dut:/ They will operate in the two minefields, and w'll give addittSnal security to shipping. but for the present the barred zone is still observed.

Captain Hall ihornpson. expressed the hope rhat when <he authorities consider the issue of war medals ihe men who did good work in minesweeplng off the How Zsaland coasts will get recognition in this form for their services