Work On New Zealand Coins At Royal Mint

Press, Volume CVI, Issue 31142, 19 August 1966, Page 5

Work On New Zealand Coins At Royal Mint

[London Correspondent.] LONDON, August 10. “I have never had to work on such fine detail before,” said Mr Janies Berry, of Wellington, designer of the New Zealand decimal coins, speaking at the Royal Mint. Removing a special pair of magnifying spectacles, Mr Berry explained that he was modelling the coins at five times their proper size, since the maximum relief finally would be as little as half a millimetre.

He was working on a model of the 10-cent Maori design in black plasticine, building up three different heights of material on a sheet of glass. Beside him were enlarged photographs of the design. A tracing of the key lines from the design had been superimposed on the plasticine and he was whittling away the material with fine metal tools.

All the edges had to be bevelled. “You can’t just have a straight edge downwards —or else, I suppose, the coins would stick in the die when they are stamping them out.”

Low relief is required. If the design were higher than the edges of the coin, great pressure would have to be put on the dies stamping out the coins, and banks would complain because the coins would not stack neatly. Mr Berry has already completed his plasticine models of the urgently required onecent (fern leaf) and two-cent (kowhai blossom) coins. From these he made first a negative plaster and then a positive plaster cast but these; are not just replicas because 1 changes and improvements; are made, and bubbles and I flaws removed. In the case of the two-cent coin, Mr Berry said he felt that the kowhai leaf was too high in relief and so he lowered it in the plaster. “The blossom is the main feature of the design,” he added, “so I left that higher.” On the 10-cent Maori carved head design, maximum relief would be given to the highspots of the design and the lettering “One Shilling” and numerals “10” would be lower in the metal, he said. Mr Berry said so far he had not met any particular problems with his task. He arrived in London last month and began work on the one—and two-cents coins, but he had been away for a fortnight and has just begun work again on the other four coins. He hopes to have all six models (one-cent, two-cent 10-cents, 5-cents tuatara, 20cents kiwi. 50-cents Endeavour) completed by the end of this month, which will mean that he will have spent six weeks on the job, or an average of a week for each model. “I found the one-cent fernleaf harder to do that 1 expected,” Mr Berry said with a smile. The edges of the leaf were tricky to define sharply. When he completes each plaster model, it goes to another department at the Royal Mint where a rubber mould is made from plaster. This is a special metallised rubber so that metal can grow on to it, and a metal model of the coin (copper faced with nickel for strength) is cast. The metal model then goes to the reducing machines, which work on the old “pantograph” principle. The model revolves round on one part of the machine and is traced by a slowly moving pointer which transmits every indentation on a reduced scale and cuts it on a piece of metal revolving on another part of the machine.

This “reduction punch” is worked on and touched up by engravers and from this is turned out a master die or matrix. This is then placed on the reducing machine again and squeezed further into metal to make a “working punch” and finally this is used to make the dies which will be used among the tools to stamp out the coins. “In some cases we make dozens of dies for a coin, in

other cases, thousands, said a Royal Mint spokesman. The reducing machines are very delicate and take a lot of setting-up. At the moment Mr Berry’s one-cent and two-cent designs (fernleaf and kowhai blossom) are both on the reducing machines, and so is an “intermediate” model of the Queen’s head obverse for all the coins designed by Mr Arnold Machin R.A. of London. The obverse will have to be made in various sizes for the different sizes of coins.

Actual production of New Zealand coins at the Mint is not expected to begin for another five weeks. Then the Mint has to make

a total of 220 million coins—--120 million one-cent pieces, 75 million two-cent pieces comprise the main orders, the other four denominations totalling 25 million coins. Mr Berry was born in London 59 years ago and went to New Zealand as an 18-year-old. He has been given his bwn desk in the engraving section of the Royal Mint, which is a most securely guarded building behind the Tower of London.

The photograph shows a close up of the . metal model for the obverse side of the new New Zealand coins on the reduction machine at the Royal Mint.