Piggyback by Kangaroo on the SNCF
from Modern Railways July 1965
Electric traction and quick long-distance overnight transits are helping French Railways to quote very attractive rates for the trunk piggybacking of road semi-trailers. A new development opens up the possibility of integrating the French system with BR's Liner trains, transatlantic shipping and US piggyback.
KANGAROO transport is a French adaptation of piggyback to the restricted European loading gauge. It employs a well, or kangaroo (French kangourou) pouch in the rail wagon to reduce the overall height of a road semi-trailer mounted on a rail vehicle. Whereas the American Railway Association standard overall height from rail-level is 15ft 6in, the European standard (Berne Conference) maximum is 14ft 0½ in. As the standard height of the French Railways flat wagon floor is 3ft 3in above rail, the maximum height of the load on it must be l0ft 9in. Most semi-trailers exceed this height. The Kangaroo wagon well contains the lower portions of the semi- trailer wheels positioned in it, to the extent of affording an additional 1ft 5in vertical height; semi-trailers by Kangaroo, therefore, can be 12ft 2in high, which accommodates a large number now in use for all-road journeys.
The high wages of tractor and lorry drivers in long-distance road transport stimulated the development of piggyback, which began, at least on any considerable scale, in the USA. There and in Canada these costs, and to a lesser extent the higher trunk speeds possible by rail transport, are the principal factors favouring piggyback; others are the safety of the consignment from accidents, high-jacking and pilfering.
In Britain distances are too short to allow any appreciable wage savings, whilst the British loading gauge restriction of 12ft 6in overall precludes conveyance of most road vehicles conveying economic loads. But in France, as elsewhere on the Continent, the centres of trade and industry are far enough apart to give scope for savings in tractor crew wages. Speed probably is of greater importance than in the USA. Within France train speeds allow overnight transits between most big centres since, as will be seen, the distances for overnight transits need be long to achieve effective economies in driver's wages.
Electric traction has cut costs
Largely peculiar to France is the fact that the low cost of electric working has reduced the cost of piggyback. Electric current is relatively cheap; the electric locomotive inexpensive to maintain and has a good availability and the train is manned by only two men - the driver (mecanicien) and his mate, (aide-mecanicien), the latter acting as guard. Obviously the low cost of running an electrically-hauled train of up to 30 wagons conveying up to 30 semi-trailers is reflected in rates which compare well with the cost of road movement of the same loads over comparable distances, even assuming that a proportion of the tractors are double-manned, as French law requires for this type of transit. Thus the rate for a 29-ton Kangaroo from Paris to Marseilles (530 miles) is £66. Another factor in favour of piggyback is the better utilisation of articulated tractors, which incur less wear and tear through fast travel over long distances; instead, tractors can be deployed with maximum efficiency on local collection and delivery.
Piggyback at 60 mph.
The SNCF runs its continuously braked-freight trains conveying road vehicles at 62 m.p.h. (100 kph.), with journey times such as 11hr for the 440 miles from Paris to Toulouse, a service by which total trainloads frequently reach 700 tons or even 1,000 tons at peak periods. The consignor can send the semi-trailer to, say, Pompadour, the STEMA (Kangaroo wagon) Paris railhead conveniently road-served and with easy access to a developing industrial area, up to 20.30 and it will be ready for collection at the Toulouse depot at 08.15. Even for Marseilles, 530 miles from Paris, the latest reporting time at Pompadour is 20.00, and collection at Marseilles is from 9.15. Joining-up and division of vehicle trains en route makes possible quick cross-country transits. Kangaroo wagons leaving St. Quentin, railhead for a large area of the North, at 15.45, are available in Marseilles from 9.15. SNCF piggyback affords a good many long-distance door-to-door transits between the ends and starts of working hours. As stated, not only long hauls offer scope for piggyback. The Kangaroo service from the new depot at Lille to Paris, 160 miles, is overnight (21.30 to 6.00). To the trader who must despatch after the day's work the possibility of saving the cost of a night's lodging in Paris for his driver is attractive.
Two forms of piggyback are practised on the SNCF: "ordinary" (on standard-height flat wagons), and Kangaroo. The former is exemplified in the UFR (Union-Fer-Route) international services. There are some fast schedules, but the trailers are restricted in height. Against this, loading and unloading are somewhat simpler than with Kangaroo.
The Kangaroo method
Kangaroo wagon transport really dates from 1960, when the International Union of Railways (UIC) recommended its development. The essence of Kangaroo is the fact of the semi-trailer being a standard vehicle. It can be a van, refrigerated transporter, tanker or special type transporter, such as for goods in power form. It has a normal wheel track, normal capacity, permits of maximum tonnage allowed by Continental or British road regulations and is equipped with standard tyre and king-pin. It differs from the ordinary semi- trailer only in: (1) the spherical coupling for loading-unloading on-from the Kangaroo wagon; (2) the steel rims between the twin tyres; and (3) the number-plate and rear under-run, which are hinged so that they can be swung clear of the guides on the wagon. If fitted to a British semi-trailer these fitments would cost at present about £250-£300, which will be lessened as production increases. Another characteristic of Kangaroo transport is the simplicity of the loading equipment needed at railhead-simply an end-loading ramp, specially fitted for alignment of the semi-trailer wheels with the guides on the wagon, and easily movable from railhead to railhead; and the special loading and unloading tractor.
The Kangaroo wagon embodies a pivoted runway which can be set by hand-lever in two positions, high (horizontal) and low (inclined). The high allows passage over the wagon of the special tractor with semi-trailer during loading and unloading. The low position is the "pouch". The semi-trailer wheels then bear against a cross-bearer of the wagon and are only about 12in above the top of the rail. The rubbing-plate of the semi-trailer rests on a landing table at the front end of the wagon and its king-pin is locked into a retaining device. Tare is 11 tons and maximum loaded weight (with a 29-ton trailer) 40 tons. Ten or eleven wagons is the optimum size of a rake of wagons to be loaded simultaneously; therefore up to three shunts could be necessary for loading one train. Normally only two men are necessary for loading: one to supervise and the driver of the loading tractor. The wagons are provided by the Societe d'Equipments des Grands Itineraires (SEGI) and by Alliance et Gestion Commerciale (ALGECO). STEMA (Societe de Traction et d'Exploitation de Materiel Automobile) operates the service, equips the railheads, accepts bookings, deals generally with the traders and pays the appropriate rates to the SNCF. Its shareholders are the SNCF (30 per cent) and road haulage undertakings. The SNCF simply works the trains - which at present may not consist exclusively of Kangaroo wagons.
Overnight Kangaroo network extending
Overnight two-way Kangaroo services now link the main French commercial and industrial centres. Besides the Paris-Marseilles and Paris-Lille links mentioned above, they include a Uzignan-Limoges service, largely to convey Languedoc wine, for which Uzignan (near Narbonne) is a railhead, to the distributing centre of Limoges over a route through the outlying spurs of the Massif Central which at present affords little scope for road competition. Another route through the difficult terrain is that between Paris and Montmelian, near Chambery, in the Savoy. This makes possible 24hr rail-and-road transits between Paris and North Italian centres, as Montmelian is well sited for the start and end of road journeys over the Mont Cenis pass. In 1963, Dutch hauliers formed the Trailstar organisation, which operates Kangaroo services between Rotterdam, chosen for its strategic situation as regards all forms of transport, and Paris, where connections are possible to and from other Kangaroo-served localities.
The road link with Italy is not likely to survive the eventual through Kangaroo services between Paris and Novara (a good railhead for Turin, Milan and other centres), which were recently being negotiated. Another international Kangaroo service which it is hoped to inaugurate is between Paris and Cologne, the latter being considered the best centre to serve industry in the province of North Rhine-Westphalia. Such international links are expected to be arranged to connect with SNCF services beyond Paris.
Difficulties of an Anglo-French service
As regards Anglo-French Kangaroo, the basic difficulty is that the loaded maximum (14ft 0½ in) height of the Kangaroo wagon infringes the British loading gauge. If semi-trailers are conveyed on the decking of train or car-ferry boats, their loading takes almost (by one account 10 times) as long as shunting the equivalent amount of trailers on rail wagons on and off a train ferry. To this there are various objections, including restricted utilisation of the wagons, a lack of space for loading at any likely British port, and possible objections by British trade unions to STEMA, or a British equivalent, functioning in the UK. Apart from this, there is the British road haulier's difficulty in obtaining return loads for Kangaroo semi-trailers from Continental destinations, partly because legal restrictions on the operation of British-owned set trailers. Nevertheless, R. A. Dyson & Co. Ltd., the British manufacturers who originated trailers of a type similar to those used in UFR services, have acquired a licence to build Kangaroo-type trailers.
Anglo-Continental Kangaroo will be facilitated by the Channel Tunnel to the extent of enabling loaded wagons run to the British Channel Tunnel terminal. On the other hand, a great deal of British industry is badly situated in relation to the Tunnel. There is the possibility of easy road movement. of semi-trailers from, say, Essex and the Midlands to a No1 Sea port such as Felixstowe, with sea transport thence to Rotterdam or Europort; this would link up, as regards Anglo French traffic, with the Rotterdam-Paris service. For the roundabout route it is claimed that a combination of low and Continental rail rates might make it a serious proposition.
As the SNCF now works nearly 250 Kangaroo wagons, there must be some hesitation about sinking more capital in further techniques or adaptations, although further study and experiments are always in progress. The SNCF recently decided to order 40 four-axle Kangaroo wagons with a theoretical capacity of 50 tons.
From Flexivan to Flexikan
Enormous international traffic possibilities, however, are envisaged from European development of the Flexivan, in experimental adaptation by Fruehauf (France), the French subsidiary of the Fruehauf Corporation of USA, of a device originally pioneered in the USA by the New York Central Railroad. This is being developed partly as a means of increasing the payload of the Kangaroo semi-trailer and partly as a container which can be adapted for Kangaroo movement on Continental railways, on Liner trains of British Railways, in the holds of transatlantic ships and hence for Flexivan movement over North American railways and roads to destinations in the US and Canada. In its original concept, the Flexivan is a demountable semi-trailer body which is slid longitudinally off its road wheels on to a specially equipped rail flat car; this has gear to rotate the body on a central pivot through 45 degrees to align it in a loaded position on the rail vehicle.
The standard Kangaroo semi-trailer, until recently restrict to 37ft 10in (11.5m) length by international road regulation cannot be extended to take advantage of the greater length 40ft (12.2m) now permitted, because of the length of the wagon well, which is itself restricted by the axles. However, if the semi-trailer body were free to slide on its rear wheel truck after it had been loaded the loading tractor could push the body back on its truck until it overhung beyond the well ; this process would be reversed in unloading. Locking attachments would secure the body in its proper position on the road wheels for road travel. Stops on the ramp and loading bridge would enable the loading tractor to achieve accurate positioning of the semi-trailer.
This is the origin of the current adaptation of the Flexivan as a container, with detachable wheels for Kangaroo movement, which is now under development. It has been named a "Flexikan". It is intended that the container shall be loadable laterally on to a Flexivan wagon and, if built to 8ft by 8ft cross-section, on to BR Liner train flat wagons. As the 40ft container without its wheels is too heavy at 40 tons for Liner train loading, a study is being made of twin 20-ton container which together could form a semi-trailer for Kangaroo movement on the new wagons besides Flexivan and Liner trains.