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'Incredible' mini artics

19th June 1982, Page 70
19th June 1982
Page 70
Page 71
Page 70, 19th June 1982 — 'Incredible' mini artics
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Squeezing beneath 3.5 tonnes gross is a real advantage to firms that don't want the bother of 0-licences. By David Wilcox

MINI-ART1CS have a credibility problem. On the road they look like vans with ideas above their station.

Is this fair? They are legitimate vehicles and nobody pokes fun at other specialised vehicles such as pantechnicons or low loaders.

The use of mini-artics concentrates on two natural break points in the weight scale. There is the 7.5-tonne (7.38-ton) gross limit under which no hgv driving licence is required. This is a small incentive and there are a few mini-artics running at this weight.

But many more squeeze in at just under the 3.5 tonnes gross weight where the advantages are far greater; no hgv driving licence, no operator's licence, no Certificate of Professional Competence, no tachograph, and no log book required . .. and more lenient driving hours.

These benefits apply equally to rigids under the 3.5 tonnes limit but the extra factor in favour of mini-artics is space. Even with a Luton body on a 3.5tonne-gvw van such as the largest Ford Transit the load space volume is usually restricted to about 1 5.6cum (550cuft). If the space in the Luton head is not usable then this figure reduces to nearer 13cum (460cuft).

The limitation on the space is due to the wheelbase options offered — normally 115-130in on this size van — which dictate the length of the body that can be fitted. This is vividly demonstrated by cambering the capability of the 3.5-tonne Dodge 535 (the smallest of the 50-Series) which offers the exceptionally long wheelbase of 4.04m (159in) enabling a Luton body of up to 26.9cum (950cuft) to be fitted.

But this is the exception rather than the rule and if you are thinking in terms of more than 15.6cum (550cuft) of load space under the 3.5-tonne-gross limit (and without resorting to a chassis extension) then mini-artics must figure prominently in your thoughts.

A typical mini-artic boxvan semi-trailer for operation at this weight will be 6.6m (21ft 7in) long, 2.2m (7ft 4in) wide and 2.1m (7ft) high. This gives an internal volume of approximately 28.3 cum (1,000cuftj.

Sheer volume is not the only ace in the mini-artic's hand; deck space is of equal importance to many operators. Our typical 3.5tonne rigid van has a deck length of around 3m (1 Oft) — annoyingly short if you want to carry a standard 12ft roll of carpet, for instance. Even discounting the swan-neck part of the mini-artic's stepframe semitrailer there is almost 4.9m (16ft) of flat deck space. And a further 1.5m (5ft) of swan-neck is more easily used than a Luton head. The only disadvantage is that the mini-artic's semi-trailer normally has wheel-boxes which intrude into the otherwise flat floor.

So, in short, the mini-artic gives around 80 per cent more volume and 60 per cent more deck space (not including the swan-neck) than a 3.5-tonnegvw Luton. But when it comes down to weight capacity the mini-artic loses out slightly to the Luton. A typical petrol-engined 3.5-tonnagvw Luton will tip the scales at about 1.6 tonnes, giving a payload (including the driver) of 1.9 tonnes. Many vans at this weight level will be constructed to just come under the 1,525kg (30cwt) unladen weight to avoid the need for hgv annual testing — they are subject to the car MoT test.

The typical 1,000cuft mini-artic semi-trailer weighs about 550600kg while the tractive unit that pulls it will add a further 1,1501,200kg, therefore giving a payload capacity of about 1.75 tonnes.

Favourite vehicles for use as tractive units for these 3.5-tonne artics are the Ford Transit 120 chassis cab with the two-litre petrol engine and the Bedford CF250 with the 2.3-litre petrol engine. Both develop around 60kW (80bhp) which seems to lz regarded as the minimur acceptable power for an artic a 3.5 tonnes. Diesel engines ar not recommended because c their extra weight — it woull cost another 150kg of payload.

VW LT31 chassis cabs are als used as tractive units but ar rather more expensive than th Ford or Bedford models.

The manufacturer of the min artic semi-trailer is also resporm ible for ccinverting the standar chassis c2b ;.it.o a tractive uni The two best known builders c these lightweight semi-trailer are Lynton Commercial Units c Gorton, Manchester, and Speci Transport Systems of Littlebi rough, Greater Manchester.

Both companies make thre basic boxvan semi-trailers t tow behind a chassis cab 1,0 0 Ocuft, 1,2 5 0 cuft an 1,800cuft. Only the 1,000cuft i designed for 3.5-tonne-gros operation although both CM panes produce a narrower ye sion of this semi-trailer (volum is 900cuft) specifically for us behind a Sherpa.

Concentrating on the 1,000cu size (which is by far the be seller) both companies' mode are very similar because the o ginal designer has been wi1 both companies. Special Trani port Systems is currently sellin 15-20 of these a year while Lyi ton Commercial Units clairr sales of about 50 a year.

Looking first at the Specil Transport Systems 1,000cu model, it is based on an alumi ium chassis with interlocking luminium floor planking. The oor is not designed to be trong enough to accept great oint loading such as a half ton allet on a pump-up truck — the )tal 1.75-tonne payload must be airly evenly distributed iroughout the trailer.

The framing of the trailer's uperstructure is 25mm square ection aluminium tubing using roprietary push-in two-way or iree-way connectors. Side paneling is 23swg aluminium heeting that is riveted to the -me, while the front panel is ne-piece grp moulding incororating a wind break. The roof ,anel is also a grp moulding.

A roller rear door is standard lthough barn doors or side oors are optional. Various tries of suspension are availble — leaf springs, torsion bar, von ride rubber suspension; rid for delicate loads air susension will soon be offered. raking is servo-assisted hyraulic with a mechanical andbrake.

All Special Transport Systems emi-trailers now have tandem xles as standard and wheels -om 10in to 13in can be accomiodated in the same wheeloxes. If 1 Oin wheels are pecified the trailer chassis can e built a little higher and the theelboxes deleted altogether, iving a flat floor. A 2in Davies lagnet kingpin is used.

The Lynton 1,000cuft model allows basically the same deign and construction but uses inde electric brakes from Sween and has an aluminium roof istead of grp. On its 1,000cuft lodel Lynton uses a single axle n the grounds that the theoretial almost ideal weight distribu tion (52 per cent on the back wheels, 48 per cent on the kingpin) means there is no need for tandem axles at 3.5 tonnes gross.

Both manufacturers quote a list price for the 1,000cuft models of £3,400-£3,450 plus vat. For operating at higher weights (but still under 7.5 tonnes) the 1,250cuft models are £4,200 plus vat and the 1,800cuft models are £5,250 plus vat.

These basic sizes can be adapted by the manufacturers fairly easily because each trailer is custom-built to order. For instance, the trailer height can be increased in 10cm (4in) steps at a cost of £150 and the length increased in 102cm (40in) steps at a cost of £285.

The conversion of the chassis cab into a tractive unit involves the addition of a fifth-wheel and its subframe, mudguards and the electrical connections to the trailer. Special Transport Systems uses a Davies Magnet 220 fifth-wheel while Lynton favours a Swiss Fischer model. Both companies charge £750 for the conversion and will install a compressor at extra cost if the customer wants the mini-artic to have its own air system like its big brothers. Neither company is keen on converting a well-used chassis cab; it should ideally be new.

Looking at the semi-trailers, there is very little to wear out. There are few moving parts and since virtually the whole structure is aluminium, corrosion will not be a problem. But they are very light trailers designed for low-density loads and the limitations of the thin panelling and flooring should be remembered. Weighing just over 0.5 tonne the trailers naturally tend to bounce quite a lot when unladen and these vibrations are probably a source of minor problems such as loose rivets.

In addition to the extra volume and longer deck length, mini-artics also offer the benefits of articulation. Theoretically you can treat them like full-size artics and run more trailers than units, double-shifting the units and pre-loading the trailers. But I wondered if these lightweight outfits can really be worked this intensively. Is a Ford Transit or Bedford CF chassis cab built for this sort of work?

Special Transport Systems and Lynton Commercial Units told me that some mini-artic operators do work their outfits in this way and that they have stood up to it surprisingly well. They pointed out that the stress on the unit is less than if the equivalent weight was being carried by a rigid; it's easier to drag a load than carry it.

Fuel consumption should also be better than that of even a smaller capacity Luton-bodied rigid; the extra length of the mini-artic is not so punitive as the high bluff front of a Luton.

The 3.5-tonne-gross 1,000cuft size mini-artics escape hgv testing because the tractive unit weighs less than 1,525kg and the semi-trailer weighs less than 1,020kg.

To ensure that the 1,000cuft size is classified as a "small" goods vehicle and so is not subject to operator's licensing, the semi-trailer is plated to 2,250kg gross — when the unladen weight of the tractive unit is added the total is less than the 3.5-tonne maximum. If the semitrailer were not plated then its unladen weight would have to be added to the unladen weight of the tractive unit and the result must be less than 1,525kg if it is to be classified as a small goods vehicle, and this is not possible using the Transit or CF chassis cabs mentioned.

Who uses mini-artics? Anyone who needs to move high volume, light loads or articles that are lengthy but light yet still keep below the 3.5-tonne-gross limit. Typical customers are small manufacturers of things such as foam products, plastic mouldings, light furniture, and lampshades. They all need to move their products but do not need full-size commercial vehicles and do not want to get involved with 0-licensing, tachographs or any of the other complications of commercial vehicle operation.

The question of advantageous driving hours is rather anomalistic. Although vehicles below 3.5 tonnes gross are subject to the old domestic driving hour rules (which are more generous than the national rules — see accompanying table) there is no requirement to fit tachographs or even use log books and so there is no apparent way of ensuring the hours regulations are adhered to.

On the subject of legal matters any future operator of a sub-3.5tonne mini-artic should be prepared to be stopped by the police who cannot believe that the vehicle does not need a tachograph or that the driver does not have to hold an hgv driving licence.

Both Special Transport Systems and Lynton Commercial Units build several other variants on the mini-artic theme including drop-side versions and smaller boxvan semi-trailers for use with pick-ups.

The market for mini-artics is admittedly small; they have specialised uses and will never be an everyday sight on British roads. But if you need to move bulky but light goods in relatively small amounts then the economics of mini-artics take some beating — they have the potential of moving almost twice the volume of goods of the average Luton counterpart.

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People: David Wilcox
Locations: Manchester

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