Old clock to ring out over Nelson again

Press, 7 March 1983, Page 24

Old clock to ring out over Nelson again

By

BARRY SIMPSON

After April, it is expected that Nelson’s Chief Post Office clock will be accurately and musically chiming the time, something the citv

has missed since the old post office was demolished late in 1970. Before the demolition began, the Kerr family members of the jewellery firm

Louis Kerr, Ltd, which had maintained the clock mechanism for 64 years, went to great lengths to see that there would be no problem when the time came to rein-.

I stall the clock m the new post office tower. , The clock, bells, and mechanism were all photographed and the framing in which the i bells sat was coded for easy reassembly.

Now, the tower, twice the height of the old post office tower, is nearing completion and is being prepared for the clock’s four faces, the mechanism, and bells.

The mechanism has not been gathering dust in some remote comer in the intervening 12 years. For the first time since its installation, the opportunity presented itself for the whole system to be thoroughly overhauled. This job was given to the Nelson watch and clock maker, Mr Henry Rodgers. After his retirement two years ago he has spent most of his time dismantling and assembling (“several times." according to Mr Rodgers), the mechanism.

His job presented some not the least of which was its transformation from a manually wound clock to an electrically wound mechanism. The clock was old. It was built by Joyce and Company, of Whitchurch, England, in 1906 — as were a lot of town clocks in New Zealand. It has a full Westminster chime and hour strike.

For 64 years, every Monday morning, a member of the firm of Louis Kerr would spend 30 minutes manually winding up the heavy weights so that they could, for the next week, gradually descend a 16.5 m weight well. The mechanism was kept in motion by the action of a 75.2 kg (1581 b pendulum, 2.5 m in length. The escapement of the clock had already been wrecked twice, during the Murchison and Inangahua

earthquakes, and since it would now be placed twice as high as in the old tower, there was fear that at that height this heavy pendulum could cause considerable damage should it come adrift during another earthquake. It had to go.

“I came up with what we think is an original idea.” said Mr Rodgers. Obtaining permission from the Ministry of Works and Development, he built a trial mechanism, a tiny synchronous instrument motor geared down to the speed of the pendulum and weighing less than Ikg. “The box. as they all call it, was fitted under one of the main beams of the clock and it works perfectly," said Mr Rodgers.

One problem eliminated. Mr Rodgers thanks Mr Trevor Cullimore. a precision engineer, of Ashburton for solving his next major problem, electrification of the winding system. Mr Cullimore had used three motors to replace the manual winding for the Ashburton clock. “Mr Cullimore exchanged the two sets of pulley blocks and long steel lines to the weight well with fairly short, endless sprocket chains on each of the three trains," he said.

“The weights now drop

only about a metre under the mechanism. The geared motors lifting the weights are controlled by limit switches. When the weight drops to a certain point it will start the motor and wind until it reaches its limit and turns off. All three motors are connected to an emergency switching system so that if any weight comes higher than its limit, it raises one of three arms of a rocker system and turns off the power to all three winding motors." he said. Being a two-way switch, it would sound an alarm in the custodian’s office. After adjustment the switch could be reset manually, he said. Mr Rodgers now expects the clock to keep perfect time — something it could not do before because of frictions, winds, and temperatures in the old clock tower. Indeed. Mr Don Kerr recalls that depending upon the time of the year, pennies or half-pennies had to be added or taken off the top of the pendulum to keep its swing accurate.

“In summer the clock tended to go slow and so the pennies would come off but they had to go back on in the winter when it tended to gain time,” he said.

The mechanism which Mr Rodgers has fitted to the Nelson clock is of a very simple and rugged construction and can be fitted to most New Zealand clock towers. The cost evidently is quite modest and not even a screw hole is required for fitting on Joyce clocks. The five bells, which will signal the quarter-hours, will be reassembled on the original jarrah bell frame timbers.

The original 2m dials are incorporated in the new 2.43 m (Bft) dials. Roman numerals 304 mm high (12in) take up the extra foot on each side. The new hands are longer than the originals and made of stainless steel. Mr Rodgers gained renown in the international clockmaking scene when two years ago a carriage clock he built won a bronze medal at the very prestigious exhibition of the National Association of Watch and Clock Collectors of the United States, the only occasion on which anybody outside the United States has won such an award.

He is at present preparing two items for this year's exhibition at Philadelphia in July. One could be a miniaturised version of Joyce and Company's clock mechanism.