Welfare of Workshops’ Employees
Heating and Ventilating the Workshops
A Modern Installation

(By A. P. Godber, Hutt Valley Workshops.)

The supply and circulation of fresh, pure air, is recognised by authorities the world over as being of paramount importance to workers, whether engaged in manual or professional duties. In the following article is described the modern “Plenum” system of heating and ventilation recently installed in our workshops.

Visitors to the new Railway Workshops in the Hutt Valley invariably comment upon the efforts of the Department to make the lot of its workshops employees brighter and more comfortable. Improved lighting facilities, clean and attractive dining - rooms, and, most striking of all, the system of heating and ventilating the various sections of the shops, are among the many improvements introduced under the workshops reorganisation scheme.

The Plant In The Making
Illustration No. 1.
Some of the intricate bends or “lobster backs” which form part of the air ducts.

In the very early days (in the old workshops), fires, other than in the regulation blacksmiths’ forges, were, for heating purposes, absolutely forbidden. The first attempt to heat the old workshops was made by the installation of a system of steam pipes laid around the machines. This scheme, however, did not prove a success, and was abandoned in favour of circular stoves, a number of which were placed at selected points in each shop. These stoves certainly increased the temperature within the various shops, but had one drawback in that, while those farthest removed from the source of heat desired an increase in the temperature, those nearest the stoves were inclined in the other direction.

In summer's heat, ventilation was effected principally by open windows and roof ventilators.

The building of the new workshops, therefore, provided an excellent opportunity for the introduction of a thoroughly up-to-date heating and ventilating system. The installation of the modern system was entrusted to the wellknown general and sanitary engineering firm, A. and T. Burt, Ltd., to whom a contract was recently let to install throughout the main workshops of New Zealand a heating and ventilating plant known as the “Plenum” system. The whole of this important work page 31 was carried out under the supervision of Mr. K. O. Hale, who has had considerable experience in the installation of similar plants overseas.

Strenuous efforts were to ensure that the new heating system would be in operation before the coming of the cold days of winter. The accompanying photos will enable the reader more readily to understand the details of the scheme, the operation of which is confidently expected to give general satisfaction.

Mounted upon a high girder platform at one end of each bay in the shops, is a motor-driven, centrifugal circulating fan, and an ingenious arrangement of piping. This latter is set up in the form of a large inverted “U,” with square corners.

A Model Of Compactness.
A heater unit fully assembled shewing the electric motor for operating the fan.

The lower ends of the pipes are screwed, steam tight, into special cast iron bases. These castings (the number depending on the size of that section of the plant and quantity of heated air required) have cored spaces in the bottom whereby any condensation may be drained off. Steam from low pressure, oil-fired boilers, circulates through sections, or nests, of these heater pipes. The duty of the fan is to draw air around and through the nests of pipes and then force it along suitable galvanised iron ducts or pipes. Supported on the cross braces of the roof, the ducts traverse the full length of each shop, two ducts to a bay. Openings, giving a downward direction to the air, are provided at regular distances along the ducts. Whether the air is to be heated, or cooled (as in summer) it is diffused over the entire area of the shop, and in such a manner as to cause no inconvenience.

The fans, being motor-driven, operate with a minimum of attention. No time is wasted stoking up, as with the old stoves, and a more even air temperature is maintained.

The “Plenum” system, moreover, provides for the circulation of cool air throughout the shops during the heat of summer. In the summer months fresh, cool air is drawn from the atmosphere, through a separate inlet, and circulated by the fans, through the ducts, in the same manner as the warm air is distributed in winter. By this means the air in the buildings will be completely changed once every hour, enabling the men to work in a cool and comfortable atmosphere inside the shop, whatever the conditions may be outside.

Some idea of the work such an installation involves may be gathered from the fact that 60,552 pieces of pipe had to be cut and screwed for the 150 heaters required. These separate units, if arranged in one line, would reach an approximate distance of 15 miles. Then, in the manufacture of the ducts and bends, no less than eighty tons of galvanised iron plates were used. The sections comprising the bends, known to the trade as “lobster backs” (see illustration No. 1), are a first-class example of plate work. In passing, it is interesting to mention that the work of screwing and cutting the heater pipes was performed by the Department's own men and machines in a thoroughly efficient manner in the Hutt Valley Workshops.

This is the first installation of the “Plenum” system of heating and ventilating carried out in New Zealand, and is on a scale not hitherto attempted in either Australia or here, and gives ample evidence of the desire of the Railway Department to make the working conditions of its employees as near the ideal as possible.

Next to the invention of printing, the most powerful instrument of civilisation that the ingenuity of man has devised, is the railway.

“… sable lazy-bubbling pools Of spluttering mud that never cools.”—Alfred Domett.
(Government Publicity Photo.)
Boiling mud at Whakarewarewa, Rotorua, New Zealand's most famous thermal region.
“… Ice upon ice, the well-adjusted parts Were soon conjoin'd; nor other cement ask'd Than water interfused to make them one.” ——Cowper.
(Government Publicity Photo.)
An ice cave on the famous Tasman Glacier (the largest glacier outside the polar regions), Southern Alps, New Zealand.