INCREASING PRODUCTIVIT) IN ROAD TRANSPORT
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by adapting vehicle dimensions to pallet sizes
N THE CONTINENT, the problem of maximum dimensions and weights for commercial vehicles has long held attention. Several attempts have been made to bring about uniform regulations for the countries of Western Europe, and the E.E.C. Council had this problem on their agenda at the September 27 meeting.
We have the impression that the fixing of maximum dimensions and weights has so far not proceeded from clearly defined points of departure. In most cases, a compromise was arrived at between the interested parties, or the argument of road safety was invoked or, it is sometimes rumoured, protection of a rival branch of transport (the railways) was a factor. The views we set forth here may perhaps result in future discussions on this subject being conducted in such a manner that only the interests of road transport will be the criterion on laying down maximum lengths and widths for commercial vehicles.
We must start by pointing out that, although nominally the 1,000 by 1,200 mm. and the 40 in. by 48 in. pallets are the same size, an accurate conversion of the British measurements into metric ones gives the dimensions as 1,016 by 1,220 mm. In international standardization this problem is solved with tolerances of, respectively, phi 16 mm. on 1,000 mm. and plus 20 mm. on 1,200 mr However, our calculations, especially concerning the widi of vehicles, are hardly applicable when these tolerances a used.
Since we have found that vehicle lengths and widths spec fled so far do not always favour the use of pallets, v) propose to concentrate on this aspect. In this article NA shall confine ourselves to the length and width of ti vehicles, though it should be pointed out that even if lengt and width were adapted to existing pallet sizes, this woul not necessarily result in maximum utilization of availab transport capacity, unless maximum permissible axle Loa( ing and location of the axles were adapted accordingly.
The Advantages
The advantages of using pallets in road transport are sti frequently under-rated. Palletized transport, using a tractiv unit plus semi-trailer with a payload of 18.5 tons, result in a saving of more than £2 per trip in pure vehicle costs z compared with non-palletized transport, owing to quicla loading and unloading. The significance of this saving clear from Fig. 1, where it is graphically repre sented as a percentage of the costs of non palletized transport for various distances. From Fig. 1 it will be seen that the use o pallets enables greater saving on short trip! am the Annual Bulletin of Transport Statistics for rope, 1960, we see that in France, it was estimated that 1960 868 million tons of goods were transported by id, of which 709 million tons, or 82%, were over distances t exceeding 50 km.
rhis shows that by far the greater part of road transport )ver short distances, and there is no reason to assume that s percentage will differ greatly in other countries. It is ar, therefore, that in road transport there is still very nsiderable scope for the use of pallets. The saving in Ade costs is only the beginning. The use of pallets also .tilts in savings in man-hours and depot space (fewer ors, higher stacking) and better supervision owing to aplified counting.
In practically all countries the authorities have laid down iximum dimensions for lorries, drawbar trailers and semiiffers. The table below gives these dimensions for Aland, Belgium, W. Germany, the U.K. and France, as 11 as those agreed upon in the 1949 Geneva Convention
id those which have been recommended by the C.E.M.T., well as the dimensions specified for the Benelux countries. The figures in this table suggest that the measurements [opted have been rounded off to whole or half metres. As is understandable, for at first sight there would appear be no reason at all for fixing the maximum width at, Y, 2.53 m. or the length at 18.36 m. Naturally, the British
easurements, if expressed in metres, do not produce iunded off sizes, but they do in feet, for 2.44 m, equals ft. and 10.66 m. equals 35 ft. However, when we start ticulating the internal net loading surface for given fixed aernal measurements and how this area can be utilized hen loads are palletized, the present maximum dimen ons are shown in a quite different light.
It is surprising that in road transport, fairly limited use is iade of pallets, in contrast with the railways where there -e actually national and international arrangements for allet pools. Accordingly, the railways endeavour to adapt le platform area of new wagons to existing pallet sizes.
A frequently voiced complaint of road transport operaws against the use of pallets is the loss of space in the nTies. Generally this does not imply that the height of le pallets (about 15 cm.) reduces the net loading height, ut that the floor area cannot be fully utilized.
tandard Pallet Measurements
The measurements of the pallet now standardized within urope are 80 by 120 cm, However, a pallet measuring 00 by 120 cm. is used in far greater numbers in some ountries (Germany, Great Britain and the Netherlands) tan the 80 by 120 cm. size. As the 100 by 120 cm. pallet ; demonstrably more efficient than the 80 by 120 cm, one, it 3 advisable to include both pallets in the survey.
In most European countries, the maximum permissible re h i cl e width is 2.50 in. The best utilization of platform ,rea is achieved if two pallets can be placed in the vehicle vith their longest sides (1.20 ma crosswise. Together, they vitt then measure 2.40 m. To this figure must be added the learance between the two pallets and between the pallets ind the sides of the vehicle. The minimum for this is 3 by cm. Hence an internal vehicle width of 2.43 m_ is a
minimum requirement. Unfortunately, this requirement has until recently not been taken into account, the majority of vehicles on the road measuring less than 2,40 m. internally.
Transport operators in the Netherlands have started using completely enclosed semi-trailers with aluminium bodywork in which the makers have managed to combine an external width of 2.50 m. with an internal width of 2.43 m. This means that only 3.5 cm. is available for each of the sides. Had the designers been free to adopt an external width of 2.55 m., the overall cost of this semi-trailer would have been some 16.5% lower, owing to the use of less expensive material; assuming chassis prices are equal in both cases. An enclosed aluminium body has been used in this case because it was the only way of keeping the internal width at 2.43 m. There are, however, many kinds of transport where a completely enclosed metal body is not essential and a wooden platform body with hoops and tilt will suffice. In that case, an internal width of 2.43 m. can be obtained with an external width of 2.55 in. and the total cost of this semi-trailer would be 50% of the one with the enclosed aluminium body. From this example, it is clear that an increase in the maximum permissible width by 5 cm. to 2.55 m. is capable of producing a considerable saving in the capital investment in vehicles.
Special Provisions
tin view of the fact that local regulations, special construction or the need for providing insulation will in many cases make it impossible to limit internal width to 2.43 m., allowance has been made in determining the length with three different methods of stowing pallets, viz, all pallets crosswise, all pallets lengthwise, and one row crosswise and one lengthwise. With pallets measuring 10Ct by 120 cm. there are three possibilities, viz., 2.00 m., 2,20 m. and 2.40 m. as against two alternatives if the 80 by 120 ern. pallet is used (2,00 m. and 2.40 m.). For road transport we are concerned with two vehicle types; tractive unit plus semi-trailer and lorry plus drawbar trailer.
In most countries the maximum permissible internal length of a semi-trailer body is 11.00 m., whilst Belgium still stipulates 11.00 m. external length. As is evident from Fig. 2. this results in losses when palletized loads are carried. It should be noted that the measurements in the drawing are net measurements, in other words, 11 pallets of 1 m. will not fit into a vehicle measuring 11 rn. internally. It is also apparent that a net loading length of 12.00 m. would be ideal. This ensures 100 per cent utilization of space lengthwise in all cases.
To these 12.00 in., we have to add additional space for the unavoidable clearance between pallets. This extra space may be estimated at 30 cm. To this figure must also be added room for the bodywork and, in special cases, an additional reserve for loads projecting beyond the pallet, or for insulation in the case of refrigerated vans. If we put this additional a mount of space at 35 cm., the external length becomes 12.65 M.
By decree of the Ministerial Committee, dated May 21, 1962, a maximum length of 15.00 m. was laid down for an articulated outfit in the Benelux countries, In addition. 1135
certain measurements are prescribed relating to the location of the axles and the fifth wheel, thus making the maximum exiernal length of a semi-trailer with a straight front, 12.23 m.
Allowing for palletized transport, the semi-trailer would have to have a length of 12.65 m. If 1.85 m. for the cab of the tractive unit and 0.70 m. for clearance between cab and semi-trailer are added to this, we arrive at a total length of 15.20 m. This is 20 cm. more than the new maximum Benelux length. From the point of view of efficient transport, only the length of the semi-trailer is important.
Another consideration in fixing the length of the semitrailer at 12.65 m., was that container transport has also to be taken into account. In the U.S.A., this mode of transport is developing rapidly and it seems inevitable that the same will happen in Europe. In the U.S.A., these container sizes are now being standardized at a height and width of 8 ft., and lengths of 10, 20, 30 and 40 ft. These large containers arealso being standardized within the I.S.O. (International Standards Organization). Owing to the big lead the U.S.A. has in the use of containers, American influence in the I.S.O. is considerable and it seems likely that the , above-mentioned American container measurements will also be adopted by the I.S.O. With the present European size limits for semi-trailers, the 40-ft. (12.20 m.) containers would not be allowed on the roads.
It will be seen from Fig. 2 that, for a lorry plus trailer, 6.00 m. also gives 100 per cent. utilization lengthwise. It would therefore be logical to adopt a net loading length of 6.00 m. for lorries as well as trailers. With the necessary allowances for cab, drawbar, etc., the total length of the lorry-trailer combination would be 16.35 m. Germany now officially prescribes a maximum length of 16.50 m.; Italy, France and Benelux, 18.00 m.
More Commercial Vehicles Although statistical records of European road transport are still in their infancy, it is possible to deduce from the scanty data available that: the number of commercial vehicles is growing; the number of tons/km. is increasing; road transport's relative share compared with the other branches of inland transport is slowly advancing and that the road capacity available for transport is being increased only gradually.
Taking into account the vast increase in the number of B36
private cars, intensification of trade as asesult of the gradu establishment of the Common Market, which trade will 1 further increased as additional countries join the E.E.C. ar the likelihood that there will be a certain concentration 4 production in the Common Market in consequence of whic average distances between producer and consumer wi increase, it would be wise to effect road transport with ti smallest possible number of units of the largest capacity, only in the interest of road safety. Viewed in this light, would not seem advisable to reduce the maximum lengi of lorry plus trailer from 18.00 to 16.50 m., especially sinc the 18.00 m. length offers many possibilities for not palletized transport and for carrying bulky goods. Eve for palletized transport, 18.00 m. is advantageous, sinc trailer length can then be increased by 1.20 m. from 6.50 t 7.70 m., thus making the combined length of lorry ph trailer 17.55 m.
The Question of Lengths Therefore, in the interest of palletized transport, the max mum width of commercial vehicles should be increased fror 2.50 to 2.55 tn. The question of lengths is shown in th table below.
In this article we have dealt only with lengths and widths A similar survey relating to maximum axle loadings anc regulations concerning the fifth wheel of semi-trailers anc the location of the axles, which may prevent the maximunpayload of the vehicles being utilized, merits attention.