H.—4o.

The Three-axle Vehicle. Transport conditions vary greatly not only in different parts of the world, but also in the different parts of any country such as ours, and consequently the requirements in motor-vehicles to meet those needs will likewise vary, but there is, and always will be, throughout the civilized world a universal desire for a high standard of efficiency in transportation with a relatively low cost in " road construction cum maintenance." In this latter connection, few would deny that the pneumatic tire of to-day justifies special mention, while many authorities would be ready to place the rigid-frame three-axle vehicle next in order of merit. As proof of the suitability of this type of vehicle for the general needs of transport, and as an indication of the present demand, it may suffice to state that in the recently compiled motor-truck schedules of England and of the United States of America many makes of such vehicles are included, and even the 30 cwt. pay-load class is represented. Everybody interested in transport is familiar with the advantages of the pneumatic tire, and likewise it is now generally known to road-controlling authorities that the rigid-frame three-axle vehicle does much less damage to the roadway through impact than the orthodox two-axle motor-truck of the same or of considerably less gross weight. Any owner of the former type of truck could confidently expect his " vehicle-maintenance charge per ton-mile " to be similarly less, and he coidd also profit through the extra gross-weight allowance given to this type of vehicle on roads with a restrictive load-classification. It has been predicted that in a few years' time the six-wheel vehicle will outnumber the four-wheel vehicle, owing to its ability to carry a greater pay-load for a given gross weight and to its less destructive effect on the roads. The " Diesel " Engine. The design, tests, and future prospects of the so-called " Diesel " engine for service in the motorvehicle have been popular subjects for serious discussion in the engineering and transport world during the past year, while much valuable information and experience obtained from the many experimental vehicles actually engaged in daily service has been published. It is to be expected that the development of such engines would be gradual, in spite, of the phenominally low cost of the fuel consumed and of many other attractive features. Marked progress has been and is still being made with the " Diesel " engine, but the weight of evidence thus far available has not yet given the manufacturer of the competitive petrol-engine cause to reorganize his works or take other drastic action in anticipation of an immediate wholesale demand for compression-ignition units. A company operating a large fleet of motor omnibuses in the Auckland area has imported and is about to commission a Diesel-engined unit which, when fully laden, will have a gross weight of over 8 tons. As this is the first of its kind to be operated within the Dominion, it will attract much attention, and. its performance and the comparative cost of operation will doubtless be watched with interest.

APPENDIX.

TABLE 1.—MOTOR-VEHICLE REGISTRATIONS, 1925-1930. Table showing the Total Number of Vehicles registered under the Motor-vehicles Act, 1924, at 31st December, in the Years 1925 to 1930.

3—H. 40.

17

(N.B. —Dormant, but not Cancelled, Registrations are included in this Table.) _ 4 , _ : : : : j Trucks (classified according to Pay-load Capacity). w Trailers. : fl - eg cj 'd T3 T3 T3 'd !. OJOfl<X> . S d.fl fl.cjcj.. flb 02 t £« Sr ° i rC <s#fi ««a g £ £3 3 © 3 S o H 31st December, Cars. ■*» . cgS «o° ° i ? a 2 2 5 £ a o2io2" 4 foe'o2Vo2'„il « fl a rC « -je o a £ "V H-pfl "?pfl jJ c_I O " ' >§ -£ oJsqjS <5 i £ £ £ I ■ O O O ! O O | ■ , I 1925 .. j 81,662 9,671 2,077 j 879 713 268 j 48 17 13,673 1,285 386 198 291 193 369 25,339 ! 123,396 1926 .. 101,462 13,056 2,827 I 1,155 824 314 48 27 18,251 1,590 465 241 432 328 455 32,101 155,325 1927 .. 111,641 15,601 3,643 J 1,322 850 340 41 18 21,815 1,143 47:7 314 535 345 422 34,593 171,285 1928 .. 1125,656: 17.057 4,302 1,465 866 347 I 48 21 24,106 1,190 421 269 689 422 460 36,116! 189,329 1929 .. 143,814 | 18,792 6,453 1,668 852 349! 51 24 28,189 1,271 372 262 945 449 501 37,349 j 213,152 1930 .. 155,189 19,894 8.068,1,807 873 350 I 51 23 31,066 1,308 306 261 1,325 465 505 37,582)228,007