Tower Silos Going Up In Canterbury

Press, Volume CIV, Issue 30947, 31 December 1965, Page 8

Tower Silos Going Up In Canterbury

A dark green coloured tower silo, about 62ft high, has been erected on the Ahuriri property of Mr D. P. Graham between Tai Tapu and Motukarara. Two English silo erectors, who have flown out to New Zealand to put up eight silos while they are in the country, worked on it over the Christmas holidays.

A second silo of similar dimensions is also being erected at Ahuriri and another smaller unit a little more than 40ft high will complete the silo installation on the farm, which will be used to supply feed to a shed being erected nearby to hold up to 400 cattle at a time while they are being fattened.

The silos being erected on Mr Graham’s property have been supplied by Boythorpe Cropstore, Ltd., of Weaverthorpe, Yorkshire.

The erectors, Messrs David Simmonds and Jack Aubrey de Lavenu of Scarborough, Yorkshire, who are employees of the Weaverthorpe company, say that it takes about six days to erect a silo of the 62ft high type. Measuring 54ft to the eave and with a 6ft to Bft high fibre-glass dome roof on top,

this silo comprises 19 rings of steel plates with a baked enamel finish on both sides. The silo is built from the top downwards. As each ring of plates is bolted on the structure is jacked up another 3ft by means of an electrically operated screw jack specially built for the purpose. Each lift takes about four minutes. Altogether Mr Graham said that there would be 17 “jackings” in the course of the erection of such a silo.

The galvanised iron bolts used to tie together each section have plastic covered heads to resist the effects of the acid in the material stored in the silo. Altogether 15,000 bolts are used in such a structure. A black mastic is used to seal each join. Mr Simmonds, who is a welder by trade, has been with Boythorpe Cropstore, Ltd., for five years. He said that they had erected 64 silos in the United Kingdom this year. In March his work also took him to Italy. Mr Aubrey de Lavenu has been with the company two years. Earlier he served in the Royal Navy for eight years. The big 62ft high units will each hold 450 tons of haylage. On Mr Graham’s property, this will consist of grass, oats, lucerne, Trudan (a hybrid Sudan grass) and Zulu grass. Mr Graham has 10 acres of Trudan growing and also an acre of Zulu grass. He is importing special equipment from the United States of America to harvest these crops, which are wilted after cutting and then taken intothe silo at 50 per cent moisture content The American equipment he will use will include a chopper, a hay conditioner, a self unloading trailer and a blower unit which are expected to arrive in Auckland about now. The green material is blown into the silo through a vent in the fibreglass dome. When the material is being blown in, a second hatch or vent in the dome is also left open to allow air to escape as the material is filled in. The material falls down onto an electrically powered spreading unit as it enters the- silo and this ensures the even spreading of the material in the tower. The spreader is bolted in position below the vent. Mr Graham had hoped to have his silos in use earlier than this and has had to turn Soil Moisture The soil moisture deficit on the non-irrigated area at the Winchmore irrigation research station yesterday morning was 150 paints compared with 454 points at the same time last year. On the irrigated area it was 74 points. This area was last irrigated on December 13 and can next be irrigated on January 9.

grass into hay. He has made about 5000 bales of meadow hay but he hopes that it may still be possible to chop this and get it back into a condition suitable for storing in his silos.

When it comes to taking material out of the silo an unloader unit operates from the top of the mass. Mr Graham says that a double auger draws the material into the middle and it is then blown out through a 2ft by 2ft door located in each ring of the silo into a tube that extends down the whole of the side of the tower. From the bottom of this tube it will be carried by auger to the 150 ft long by 80ft wide feeding shed that is being built alongside Mr Graham’s set of silos. The third smaller silo will incidentally hold 150 tons of barley and peas. The material from the silos will be carried automatically along the centre of the feeding shed and will drop down into a feeding trough which will serve 10 pens arranged on either side of the trough. These pens have been designed to hold about 40 cattle each and it is expected that cattle brought in at about 18 months old will be held here for about three months putting on an estimated 31b to 41b of liveweight a day. At full production it is expected that upwards of 1000 cattle a year will be turned out of this unit. Mr Graham hopes to have the unit working by April 1.

When the silo erectors have finished at Mr Graham’s they will go on to Mr John Harris’s at Lansdowne Valley, Halswell, where they will erect one silo for holding haylage and another for barley to be used in conjunction with another cattle fattening installation.