BATTLE OF THE BRAKES.

Dominion, Volume 3, Issue 833, 3 June 1910, Page 6

BATTLE OF THE BRAKES.

ROYAL COMMISSION REPORT. AUCKLAND TRAMS UNDERBRAKED. "WELLINGTON' AliSO- FOUND WANTING. TJic report of Professor Scott, of Christchurch, and Mr. A. L. Beattie, of the Railway Department, who were appointed by the Government to enquire into the efficiency and suitability of the brake system in vogue oil the Auckland City aud Suburban Electric Tramways was before Cabinet yesterday. It. was approved generally, but nothing will be. decided at present, so fax as the report relates to the appointment of an inspecting electrical engineer is concerned. In beginning rheir report the Commission states that the diversity of brakes and opinions made full inquiry necessary. In Auckland the brakes were the hand wheel brake for service stops, and the Spencer brake for steadying the car 'on gradients whilst ttlie motormen are instructed in tho use of No. 2 and No. 3 electrical emergency brakes, and a couple of cars are with a pneumatic wheel brake. In "Wellington and Dun-idin the cars carry the hand wheel brake, and the Newell track and wheel brake. The Commission found that by errors of under-estimation of the weight of cars and over-estimation of the mechanical advantages .of the brakes in use the cars at Auckland were distinctly under-braked. In Wellington the council brought evidenco in iavour of the -magnetic brake in hilly well as, level localities. Experiments of tho efficiency of tho | magnetic 1 brake were, however, not altogether satisfactory. Upon the question of tests the commission stated, inter i alia, that various cars in Auckland were found to weigh 52 per cent, in excess of their reputed weight, in Christchurch the excess was 30 per cent., whilst in Dunedin it was only 7i per cent. It was found that the behaviour of the magnetic brake when coasting oil the Brooklyn line at a gradient of on© in 12, and when making stops from speeds below eighteen 'miles per hour, was satisfactory, and the stops were exceedingly good, but above tho speed of nineteen miles per .hour the current flashed round the commutators, inducing skidding and lurch- ! ings with uncertain l stops. During various tests it was found that the.limits of 1 effective operation for the magnetic brake lay between three and twenty miles per hour, but that there were no limits to I the speed at which the pneumatic wheel I brake might be applied. [ Review of the Different Brakes. As regards general conclusion the commission were agreed: (1) That the hand wheel brake is not a suitable appliance for the safe control of a car exceeding fifteen tons. (2) That the pneumatic wheel brake, is a reliable and efficient brake for cars of any weight running at any practical speed on the level or at moderate gradients. ... (3) That where gradients exceed t one in twenty it is desirable, and where they exceed one in fifteen, it is imperative that some form of track brake should be used. ... (4) That the rheostatic brake is an undesirable arrangement for level or undulating districts, but with a carefullydesigned motor equipment of, ample capacity constitutes a valuablo accessory for uso in descending long grades. (5) That tho , Newell electro-magnetic combined track and'wheel "'brake is ex-ceedingly-efficient, and" in;.careful hands and within certain speed limits, is reliable, but the necessity for avoiding too r'apicj reduction nf iucureuit huiders it. (in the hands of a not absolutely cool motorman) . liable to flashing-over and skidding, and failure, especially in the case of sudden .emergency. The more satisfactory results obtained in Dunedin as compared with "Wellington were probably largely due to the whole of the car equipment at the former place having been supplied by the manufacturers of the. brake, and the motors having been designed with a view to its use. . . . The limitation of the speed at which. this, brake is effective constitutes a .very real- source of danger where steep gradients 'are worked. It is desirable that a -certain skiddingproof "Westinghouso attachment should be tested in the Dominion .with a view to its ultimate adoption by the tramway systems on which the magnetic brake is used; also, that on such systems all ears running on gradients of one in fifteen, or' steeper, should be fitted with the'improved mechanical detachment, and on, cars fitted, with' tho magnetic and with hand-wheel brakes all coasting should be done-on the former (electric or hand application), and its use should bo compulsory for both service and emergency stops It is necessary, in order to ensure the, emergency brake being in working condition, and its application instinctive, -that both the emergency apd tho service stops should be made with the fcame apnliance, and differ only, in the-degree of force used; (6) That the standard both of the design and construction of tramway trac?: gear is, as a whole, below that dictated' by railway practice.

State Supervision Suggested. After referring at some length to defects in the Auckland brakes the commissioners state that they lxad also considered. the working of the existing law and tho necessity or expediency of any ne\v They have found that in Wellington, Christchurch, and Dunedin a liigli standard of upkeep and efficiency of equipment is maintained. The standard maintained on tlie Auckland tramways is below that of other lands, but there is evidence that great improvement had been effected by the present officers who appeared to be desirous of using all means at their disposal to place their equipment in a more satisfactory condition. It is their opinion that if fresh legislation necessitating closer inspection be introduced it is desirable that any inspector appointed should be an electrical engineer of high qualifications and extended experience of tramway work whose professional status would be such that his assistance would be welcomed by the ■ executive tramway engineers. Tho commissioners also considered it to bo desirable for the Government to bo able to take powers to be able if necessary to insist on any tramway system being equipped and worked with due regard to the safety and convenience of the public.

Council's Expert Interviewed. Mr. Stuart Richardson, tramways manager and electrical engineer to the Wellington City Council, was interviewed with regard to this report by a Dominion" representative last evening, and made the following statement:—"Tho Tramways Department has already ordered two of the skid-proof attachments recommended by tho Commission. We were looking into this matter before tho Commission sat, and wo had written to England to- our consulting engineer for lull data on' tho matter, as we did not find it possible to get the information in New Zealand. Up to the present we have not received any reply." Mr. Richardson explained that if tho cars were fitted with these attachments the requirements of the Commission would be met. Two attachments were required for each car, and tho order already sent Home was intended for trial jmrposes. Mr. Richardson, of course, coulu not «y what would be dono by'the City Council, and ho declined to express any opinion for publication on the conclusions arrived at by tho Commission. If skid-pvoof attachments aro eventually adopted by the council, two will be required for each car, and the total cost, it is understood, ivill probably run into several thousand pounds.