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Time was when long-distance drivers were consideed as modern-day gipsies.

But today's sleeper-cabs are designed to give them the comfort they need for maximum efficiency — and safety. We booked into seven cab hotels for our annual cab night out.

• "We're opposed to sleepers — drivers should by rights book into hotels. They are no more than modern-day gypsies, and they are entitled to a better status in life." Remember those words? They belong to the Transport and General Workers Union's national road transport group secretary, Jack Ashwell. Mind you, that was over eight years ago and sleeper cabs have come a long way since then.

Back in the early eighties many drivers undoubtedly had a rough deal. Commercial Motor can recall a visit to a major food distributor at the time whose drivers were expected to construct a bed across the engine cover of a day-cabbed Leyland Buffalo using discarded cushions from old sofas.

Thankfully those torture chambers are a thing of the past, or should be, for if operators expect to get the best out of their drivers then they should at least give them decent materials to work with.

Last year five members of CM's editorial team spent the night in a quintet of 38-tanners to see what they had to offer. This year we repeated the exercise with seven new tractors.

In addition to our views on the snooze we have compared the controls, suspension and ride comfort, using sophisticated measuring equipment at the Motor Industry Research Association test track at Nuneaton.

Our seven trucks would all claim to be state-of-the-art vehicles, so the age of some of their designs might come as a surprise — two of them started life close to 15 years ago.

Given the cost involved in producing a new cab, it's hardly surprising that manufacturers are keen to keep them in service for as long as possible.

Leyland Daf Roadtrain

When the merger between Leyland and Daf was first announced back in 1987 rumours about the future of the Roadtrain flew thick and fast. Would it be dropped the minute the new 95 Series arrived? There was certainly no doubt in LD's mind that it would remain for the "foreseeable future" — whatever that means — and two years on it is still around, although some high-powered models have been dropped as part of the rationalisation of LD's heavy truck line-up.

The Roadtrain is very much a breadand-butter fleet machine: the more discriminating small fleet/owner-driver buyer is likely to opt for the 95 Series. Not that there isn't some cross-over, but the principle is now firmly fixed in the company's marketing mind.

The 200kW (268hp) Cummins L10powered 1728 is an excellent example of a no-frills "gaffer's motor". The T45 cab broke new ground when it debuted back in 1980, epitomising the then nonaggressive cab design philosophy. Apart from the introduction of the high-roof Interstate option (now only available on the Perkins-powered 20.33 twin-steer) it has changed very little.

The original check and grey interior trim was changed to the current maroon finish in 1985, and an Isringhausen airsuspended driver's seat has replaced the previous Chapman Brerrishey seat. The passenger's seat is still mechanical.

The 1728's cab, known officially as the C51 P "premium day cab", comes with a single bunk (twin bunks are only offered on the Interstate). It is suspended by rubber bushes at the front with a transverse leaf spring and shock absorbers at the rear. If you want a more sophisticated ride you'd better buy the 95 Space cab.

The all-steel unit has alloy cab steps and some plastic on the front to keep corrosion at bay. The front mud wings are also made from a composite material, and on the subject of corrosion resistance the Roadtrain cab comes with a five-year anticorrosion warranty and a two-year paint warranty, subject to the usual terms and conditions.

Standard features include heated mirrors, pre-wired radio installation (speakers and aerial, but no radio), adjustable steering column and Sundym glass all round. What it doesn't have as standard is a night heater, and this adds an extra i:480 to the list price. Fog lights also cost extra.

This does not pretend to be a premium truck, so it would be all too easy to make unfair comparisons with the others in the test. It was, however, a pleasant surprise to find that the Roadtrain was fairly well equipped, and that the driving position was comfortable. The spartan nature of the trim gave the vehicle away somewhat, but the instruments are easy to read, even if the units of calibration are best left to mathematicians.

Instrumentation comprises a rev counter, speedometer, fuel, oil pressure and, water temperature gauges, a voltmeter and four air gauges (the Roadtrain has six air tanks). The wipers, controlled from the steering column stalk, give two speeds and an intermittent. The horn, headlamp dip and flash, screen wash and indicators are also controlled by a column stalk.

The heater controls' are simple, but very effective, especially the side screen clearing outlets. Other features include quarter light windows, a rear coupling lamp, an optional Phillips radio cassette and asymmetrical windows so the driver knows which side to get in.

The electric windows have individual controls and there is a 12V accessories socket. In all this is very much a cab for the occasional night away from base, but it is comfortable to drive, and shaped up surprisingly well against the fleet flagships it was compared with.

First impressions when bedding down for the night were of a lack of space. You cannot stand upright in any part of the cab, and changing must be done either kneeling on the bunk or perched on the passenger's seat. The next thing you notice is a lack of storage space, with no large internal lockers, The grey and maroon colour scheme is tasteful, with carpeting on all exposed floor surfaces except the footwells. The quality of the furnishings seems adequate, but overall the interior leaves the impression of a mid-range Austin Maestro: nice, but not that nice.

Curtains along the side of the cab are fiddly to fix, and it is unlikely that the popper studs which secure them will stand the test of time (one had broken already). There are no front curtains, just driving blinds, and the curtains at the rear are not totally opaque. Having criticised the cab for lack of space, it must be said that same compactness was a boon when it came to the length of time taken for the cab to warm up. The heater took only 14 minutes to raise the temperature from an ambient 9°C to 21°C, and could maintain that temperature with ease. When the heater was switched off, however, the warmth did appear to drain from the cab quite quickly.

The bunk itself was satisfactory, with plenty of length and an adequate 100nunthick foam mattress (but no pillows). Interior lighting was good, with two smaller lights and a large fluorescent strip; there was no small reading light by the bunk, however. A good radio-cassette player provided the in-cab entertainment.

Mercedes-Benz 1729LS

It says a lot for the old "new generation" cab that more than 15 years after it was introduced, Daimler-Benz is still happy to use it, albeit in revised form, on the latest generation of Mercedes-Benz SKI Powerliner 2 heavy trucks which debuted last July.

As with the Volvo F16, much of the attention given to the SK range has ben directed at the new Powerliner 2 engines, notably the 353kW (480hp) vee-eight lump in the top-of-the-range 1748.

As a result, the cabs have been pushed rather into the background, but they have not been ignored, gaining a full-width black grille and a larger front access panel. The mud wings, grille, three-piece front bumper, top and bottom spoilers and side deflectors are all made of plastic.

The most obvious external change, however, is to the doors, which now have the familiar sloping window line a la Mercedes LN2 light-middleweights.

Our 1729 was supplied with the fulllength, all-steel L sleeper cab which comes with twin bunks as standard, (the top one folds out of the way). For those operators not planning to spend many nights away from home there is also an optional short sleeper cab, which shaves 2450 from the price of the normal L cab.

The 1729's cab is suspended by Usprings with shock absorbers and anti-roll bars at the front and a multi-leaf spring with dampers at the rear. Not so long ago Daimler-Benz was still fitting a fixed driver's seat, arguing that, like Volvo's FL10, its cab suspension was good enough to make an air seat superfluous.

That policy has changed and an airsuspended driver's seat is now fitted next to the mechanical passenger's seat. Other standard items on the 1729, which qualifies as Mercedes-Benz (UK)'s fleet machine, include an adjustable steering column; external Powerliner sun visor; heated rearview mirrors with electric adjustment on the nearside; electric codriver window operation and a tilt roof

hatch. There's also a radio/cassette player and lockable document case between the seats, headlamp wash/wipe and front fog lamps.

Being a Powerliner 2 model at 213kW (290hp), the 1729 has Daimler-Benz's EPS (Electronic Power Shift), which replaces the conventional mechanical linkage between the gear lever and gearbox with an electro-pneumatic connection, operated by a stubby gear-selector lever.

Mercedes-Benz (UK) is prepared to offer a manual change to rental fleet customers who prefer not to have EPS (CM 1 December 1988).

The 1729 cab does not have a specific anti-corrosion warranty; simply the vehicle's usual 12-month/unlimited-distance cover.

While air-suspension is standard on our 1729LS model it also sported a number of optional extras, including the air management kit of top and side deflectors which retails at 21,312; a middle seat with belt at 2288; seat belts on both driver and passenger seats at £144; and a night heater worth £440. The most expensive option fitted is the joint ABS/ASR anti-lock anti-wheelspin packge which costs a hefty £3,150.

Mercedes' L-type twin-bunk cab is not quite as restrictive on internal height as the 17.28 Roadtrain, and access to the air-suspended driving seat is a little easier too. Unlike our Mercedes road test vehicle, which had a centre seat for demonstration use, there are only two seats, both of which are well upholstered and fully adjustable. Steering wheel position can be adjusted to cater for drivers of every shape and size.

Beneath the doors contoured top edges with their floppy ash tray covers, there are oddly-shaped pockets to complement the document stowage space above the windscreen and the standard locker be

tween the seats. The cab floor is covered with a plasticy matting, and with no threshold lip it can be cleaned out quite easily. The steps are rubber covered and might be slippery with dery or water on them.

All switches and instruments are angled towards the driver and a single stalk switch operates direction indicators, windscreen wipers, main-dip beam and horn. Switches are grouped to the left in order of priority, while the passenger window switch is to the extreme right of the instruments, all of which can be seen through Mercedes' Cyril-Smith-junior steering wheel.

With only one window winder, driver and co-driver have a pair of fan heater speed controls with which to play tunes on the vehicle's very comprehensive heater/ventilation system.

The 1729's air-suspension remote control box lives by the drivers seat, so Mercedes has positioned the Eberspacher on the passenger side and the outlet duct is on the opposite side of the cab facing forward, just where the driver would stand to get changed (if there was room).

Your reaction to sleeping in the cab of a 1729 will probably depend on your lifestyle. If your idea of roughing it is to turn the central heating down, you're probably best advised to stick to a days-only driving job. But if you've slept comfortably in a caravan or on a friend's sofa you'll have few faults to find with the Mercedes (or any other modern sleeper cab for that matter).

After all, there's a thick foam mattress long and wide enough for any but the tallest and widest to drivers, complete with a couple of small pillows. There are no perceptible draughts and an effective cab heater raised a rc ambient air temperature to a shirt-sleeve temperature within a very few minutes although only the Renault took longer to reach our 21°C target.

Having scaled the widely spaced trio of steps a driver entering the 1729 cab for the first time is likely to appreciate its restrained, up-market appearance. A mixture of light-grey fabric and dark-grey plastic trim seems eminently practical, but the blue, brown and white patterned seat covers, while attractive enough, were showing signs of wear.

Climbing out of the driver's seat to the bunk is an awkward business. There is insufficient headroom to stand upright so our tester gave up and undressed lying on the bunk.

Once the upper bunk is folded down it leaves the lower bunk out bounds for claustrophes and, bearing in mind the cab's minimal storage space, doubling up would not be fun on a regular basis.

There is a space below the bunk big enough for spare clothes and some food; apart from that there is a large, but openfronted storage space over the centre of the windscreen and small door bins. Except a couple of plastic hooks there is nowhere convenient to store clothing at night: during the day elastic luggage nets convert both bunks into huge storage areas.

Once installed in the bunk there was little to complain of: asking for featherfilled pillows in place of sponge would smack of nit picking. Light-grey striped curtains extend round from the rear of the cab sides on smooth-acting runners to meet in the centre of the windscreen and Velcro together for insulation and privacy; curtains can also be drawn across the front of the bunk.

Interior lighting is excellent with a dualintensity diffused light over each seat as well as map-reading spot lights and reading lights by the bunks.

A good-quality radio/cassette above the driver's seat features digital tuning with plenty of presets; a remote to allow the driver to turn it off from the comfort of the bunk would have made the cab that bit more luxurious, as would some sort of oddment storage space by the bunk, standing room for changing and somewhere to hang clothes.

The Mercedes cab features the high quality you would expect from this manufacturer, but as a bedroom it could easily be improved with a little advice from the working drivers who will actually have to live in the thing.

Renault Turboliner R365

The ancestry of the cab fitted to the 264kW (359hp) Renault R365 Turboliner, launched at last year's Motor Show, can be traced back to an original Berliet design of the mid 1970s. Before sampling it on the current Renault Truck Industries R-range, UK operators would have already seen its predecessor on the old Berliet TR tractor, as well as on the late, and not-so-lamented, Ford Transcontinental. Despite being relatively long in the tooth it has withstood the ravages of time surprisingly well — although, like Volvo's F cab, its replacement really can't be that far away.

During recent years it has been facelifted and revised with the original brown interior trim material now superseded by a deep blue finish. The instrument panel and dash have also been reworked.

The R365 twin-steer in our test features the optional GRP Turboliner highroof extension to the all-steel cab. If you order an R-range Turboliner model you automatically get twin bunks as standard, along with a neat removable document/ attache case built into the centre console and a suit hanger.

For your money you'll also have heated mirrors; a front air dam with four fog/spot lights; side air deflectors; an lsringhausen air-suspended drivers' seat; electric windows on both sides; a dash-mounted headlamp adjuster; a roof hatch and an adjustable steering wheel and column.

Like a number of other tractors on our test a radio is extra and so is a night heater: together they boost the list price by £648.

The stunning paint finish on the 6x2 R365 certainly wasn't standard — our Turboliner tractor's star-burst livery was originally prepared for the Motor Show.

Suspension on the R-range cab is handled by a four-point coil spring and hydraulic damper arrangement, which was favourably received when we tested the R340 Turboliner back in October 1986.

Its all-steel construction is extensively treated but does not have a separate warranty from the 12-month/unlimited distance cover on the whole truck.

There is some use of composite materials on the front of the cab, and the mudwings are plastic.

With four well spaced steps, (the bot torn one is set in the air dam) it is an easy climb up to an uncluttered but wellappointed interior, trimmed in warm greys and blues with a similarly coloured floor covering that looks durable and should be easy to clean.

Its fully adjustable steering wheel gives a clear view of the instruments, while the warning lights, unlike those in the other trucks, are arrayed to the left of the gauges. There are two stalk switches on the wheel; lights and indicators to the left and wipers to the right. Other controls such as the window winders are within easy reach, except for the illuminated heater/ventilation controls which are a stretch away in the centre of the dash.

A manual headlight adjuster allows the driver to compensate for changing loads. The control is well sited behind the gearlever, unlike the exhaust brake button, which is too close to the seat to be comfortable for short drivers who need the seat close to the wheel.

Broad forward views are only broken by the A-posts, and a good set of mirrors make up for the lack of windows behind the driver. With only 600km on the clock the gears were understandably stiff, but the clutch pedal, though easy to hold down, was fairly heavy to operate, requiring 20kg of effort from the driver.

The R365's sleeper unit makes the most of its internal dimensions and feels very spacious with tasteful, felt-like lining material and a pleasant colour scheme.

Like most cabs, the pillow provided is rock-like and the bunk is none too soft either. Our driver used the lower one but there seemed no shortage of space in either. At 1.78m he had sufficient room to stand upright on the engine cover to dress, but the cab lighting leaves a lot to be desired. The lamps provided were more like glowworms, which made reading difficult after dark.

There is plenty of deep stowage space in the headlining; the mirror behind the centre cupboard door is useful, and the hanging clothes holder is handy for long trips. The Philips radio is quite a good one but lacks a simple bunkside on/off switch when closing down for the night.

Scania R143MA

Scania's 3 Series cab, launched in Britain Last spring, is a product of the "evolutionary rather than revolutionary" design school, having gown out of the old 2 Series range. The latter's rather aggressive, angular face has, however, been softened a little with the use of more flattering, curving side deflectors.

Scania took its time in getting around to producing a high-roof version of its heavy tractor cab, but it finally did so with the launch of the 3 Series, which is offered with the optional Topline cab on selected R models. Unlike many of its rivals, the roof extension is steel, rather than a composite material.

By virtue of the extra 220mm, the Topline cab provides an internal height of 1.7m — not as much as the Globetrotter or the Stratocruiser, but sufficient for most drivers.

The Topline sleeper cab comes with two bunks and a four-point air suspension system which keeps it level by means of two load-sensing valves. If the comments from our recent test of the R143 450 Topline tractor are anything to go by (CM 20-26 October) then there will not be many complaints about the ride.

The automatically adjusting airsuspended seats come with seat belts: the passenger seat can also be pushed all the way back to the rear wall to make room for the driver to undress.

For the more pampered among us, the Isringhausen seats follow the Scania tradition of having a heat pad in the bottom squab. It is thermostatically-controlled, switching on when the temperature in the cab falls below a certain level.

By far the biggest change within the 3 Series (apart from its new engines) is the redesigned dash which now curves round the driver placing, everything within easy reach.

Sitting in the standard Isringhausensprung seat of the Scania 143, looking at the new curved dashboard, one can see the central rev counter and speedometer even with one's hands on the wheel.

The ventilation system has been updated, along with the interior trim panels, while central locking comes as part of the Topline package.

A Scania with a Topline cab doesn't come cheap, but you do get a lot for your money such as electric windows, adjustable steering column, headlamp wash wipe, a neat multi-purpose lockable box on the centre console and a Webasto night heater which not only pumps hot air into the cab but also warms the water in the heater matrix, ensuring that the driver has plenty of warmth at the start of a cold morning's work.

There is a five-year specific cab warranty on the Scania, subject to annual inspection against corrosion from the inside out.

Our 143 450 Topline Scalia came with a number of non-standard goodies including the full wind deflector/side skirt kit which runs out at £960. The other item you will have to pay for on the Scania is a radio, which costs £138. Along with other manufacturers, Scania finds that operators and drivers either prefer to get their own, or let the dealer supply it.

Standard instruments include water temperature, fuel level, an ammeter, oil pressure and two air gauges (there are five air tanks).

Two steering column stalks control the indicators, two-speed and intermittent wipers, headlamp dip and flash. The instrumentation and switches are all one would expect from a top-of-the-range intercontinental truck.

Other features include a separate park and trailer brake that other manufacturers wished they had kept on their vehicles, headlamp beam adjustment, heated mirrors, a hand throttle and a plethora of idiot lights.

The heater has a four-speed blower and Star Wars-type face-level ventilators, but both these systems seemed only average in their efficiency. There is no recirculation of the interior air, but all the fresh air, we are told, is filtered before entering the cab.

Although we only had a short time with the vehicle it seemed a pleasant truck to drive, being both fast and easy to conduct. The driver has plenty of room to move around, the pedals are set at a convenient height and have space around them for those with large plates.

Commercial Motor's test night was not very cold, and the Scania 143's cab proved to be a marvellous vantage point from which to observe a short-eared owl's magnificent progress round the almostdeserted tracks.

So the Scania's cab earns full marks from the British Bird Watcher's Society, but what about the sleeping arrangements? Undressing is helped by a massed bank of lamps: reading, overhead, and otherwise. It is not helped by the low headroom.

The sliding passenger seat that looked so impressive at the launch of the 3 series cabs moves rather unsteadily back into the space once occupied by the end of the bunk to allow room for the average 10year-old HGV driver to stand up in when changing his school uniform.

The test truck was a thoroughly cleaned, and well-nigh pristine example of Scania art in the metal, and yet the seat runners had still become clogged with dirt tomake moving it a real chore. If one elects to get undressed in the space it provides there follows a semi-naked scramble to get the bed-hungry seat back in its lair to reclaim the sleeping arrangements, such as they are.

Once ensconced in the bed there is plenty of time to admire the pleasant twill upholstery and sink back into the firm, comfortable bunk.

There are reading lamps on both sides of the cab and a clever cab heater warms the radiator water rather than simply providing hot air.

The central console provides a useful alarm-clock rest, and there are twin magazine racks and a pair of overhead lockers. The radio is very nice to listen to, but the ignition has to be on first, and the driver faces another outing to reach the thing to turn if off before falling asleep. The rest of the cab is finished with rubber mats, which may upset the hedonist in us, but does allow for easy cleaning, and a long, smart life.

It was a comfortable night, all in ail; the Scania's cab is somewhat cramped, but not an unpleasant environment.

Seddon Atkinson Strato

If you're looking for the most modern cab among our seven contenders look no further than the Seddon Atkinson Strato. The basic design is by no means unique to the Oldham-based truck builder, however.

The result of the joint Daf/Enasa "Cabtec" project, the same cab, apart from the badges, can be seen on top of both the Leyland Daf 95 Series and the Pegaso Troner, built by Seddon's Spanish owner Enasa. Like the 95 and Ironer, all Strato cabs are produced in Spain in a million purpose-built plant.

The Strato cab comes in three different forms; day, sleeper and the top-of-therange high-roof Stratocruiser sleeper — no doubt the marketing men from Seddon Atkinson were thinking of the pioneering piston-engined airliner built by Boeing when they came up with the name. All Strato tractors come with a sleeper cab as standard, with the Stratocruiser or day cab offered as an option. The only exception to this rule is on the most-powerful 1740C tractor, driven by the 14-litre 298kW (400hp) Cummins Super E engine, which has no day cab option.

For our test Seddon Atkinson supplied a 1740C Stratocruiser. It is all-steel with a five-year warranty against corrosion, which will doubtless reassure operators mindful of the problems experienced with rust on Seddon Atldnson's earlier tractors.

Like the 95 Series, the Strata cab features neat plastic inserts along the bottom of the doors — a favourite bridgehead for corrosion — as well as extensive use of plastic in its front panels. The quarter deflectors and front bumper outer skin are also made from GRP.

Compared with its rivals, the Strato has an above-average cab suspension system. Day and sleeper cabs have a four-point coil-spring system, while the Stratocruiser, like the Leyland Oaf 95 Series Space cab, has an electronically controlled active air suspension system with levelling valves that govern cab pitch when driving, and cab dive when braking.

The Stratocruiser also comes with an air-suspended driver's seat featuring twochamber lumbar support. Like the Scania 3 Series wheel, the Stratocruiser steering wheel is adjustable for height and rake.

Large areas of grey plastic are not inspiring, but are commendably practical. Instruments include a rev counter, speedometer and water, oil-pressure fuel and air guages. Steering column stalks control the horn, flashers, headlamp dip/ flash and screen wash/wipe.

As befits a modern top-of-the-range cab, the Stratocruiser boasts an impressive array of standard items including double bunks; electrically operated, heated, tinted mirrors; electrically operated roof hatch; front air dam with twin fog and spot lamps; front quarter deflectors; head

lamp pressure washers; remote headlamp adjuster, three-band radio/cassette; an alarm clock for those early morning getaways and a night heater.

There is also a built-in wardrobe (but as yet no kitchen sink).

For those interested in fine detail, there is a fold-out step in the front bumper to help the driver remove the remains of dead insects from the screen — and, considering its large frontal area, Stratocruiser drivers will be kept pretty busy doing just that come summer.

Seddon Atkinson's Strato cab is, of course, the same as the Leyland Dafs 95 Series tested last year. However, this year's model has twin bunks, interior trim is blue instead of grey and the wardrobe is on the passenger's side.

Without an overhead locker on the offside there was plenty of room to stand up, with 1.9m of headroom. Storage space is abundant, with overhead lockers including a shelf over the driver's head, a wardrobe and an under-bunk locker; decor is restful and the bunk covering is removable to allow washing. It is also easy to move around in the large cab. Nonetheless, the detail could be improved.

Over-bunk lights (one at each end) are dim, very yellow and only fitted above the lower bunk_ For reading the main cab lights are required and the switches for these are located in the console above the driver's head. Relocation to the centre console by the gear lever would be ideal for driving or resting.

A cab heater is a standard fitment on this cab; ours had the controls find to the B-post by the driver's right ear. This meant that with the curtains drawn the controls were trapped between the cab skin and the curtain, which is both inconvenient and detrimental to operation of the thermostat. Again, positioning it in the centre console would be preferable.

Once in there, the bunk is firm but not hard and of ample proportions but no pillow is provided.

This Strato cab offers excellent cornmodation for driving and those having to spend the night in it, but a couple of wiring changes could make it better.

Steyr 19S31

It's ironic that one of the newest contenders in the UK tractive unit market should also have one of the oldest cab designs — 'certainly compared with its rivals in this test. It does, however, say something for the original distinctive wedge-shaped design that it can still hold its own against considerably younger components.

That's not to say that Steyr is happy for things to continue that way. A replacement is being developed and is likely to appear along with a new 298kW (400hp) in-line engine within the next two years.

The original Steyr heavy truck cab dates back to the early 1970s, although over the years it has received its fair share of facelifts. But the most interesting aspect of the 19S31 is its sleeping arrangements.

Like the Seddon Atkinson Strato and Renault R365, it comes with a high-roof cab extension but on the 19S31 the top bunk is effectively encapsulated into a top sleeper pod, while the bottom bunk is sited conventionally behind the driver's seat. The whole process has been completed so neatly that the top sleeper pod stays within the overall lines of the cab, forming an effective wind deflector above the normal cab roof line.

To ensure that the driver can undress easily the area over the passenger seat and the central console has been left open, allowing him to stand up without hitting his head on the floor of the top sleeper pod. The concept is so simple that it is surprising that more manufacturers haven't adopted it on their twin-bunk cabs.

The 19S31's cab shell is steel with the top pod built from GRP, which is also used on the front grille, bottom bumper and the front mud wings. It is suspended by rubber bushed mountings on the front with coil springs and shock absorbers at the rear.

Although the 19531 is seen as Steyr Trucks (IJK)'s flagship, a number of items found as standard on its rivals are only offered as options. The most notable of these is the Eberspacher night heater, which adds £450 to the 19531's admittedly competitive £39,850 price tag. According to Steyr Trucks (UK), having the same heater fitted at Steyr's Austrian factory would cost considerably more: hence its option status in the UK.

You also have to pay for electric windows on the driver's side (standard on the passenger side) and for an electricallyoperated nearside mirror, should you want one. Standard items do include twin bunks, headlamp wash/wipe, an automatically adjusting Isringhausen driver's seat and an aerial built into the windscreen, along with front air dam with four spot/fog lights.

Steyr's 19S31 comes with a five-year anti-corrosion warranty, subject to inspections, and while we would be the last to suggest it was for anything other than routine maintenance, we couldn't help but be impressed with the 15-piece tool kit which comes inside a sturdy case with every Steyr tractor.

Some of the incidental cab furniture, such as the ashtray, cassette holder and map light, seem a trifle gimmicky, and this is a pity: the cab interior features some novel ideas. The Steyr's instruments consist of a rev-counter, speedometer, water temperature, oil pressure level, fuel and air gauges with a Mercedes-Benz-type steering column stalk to control the horn, wiper, indicator, and headlamp dip/flash functions. Very simple heater controls provide a two-speed blower, but no air recirculation device. Other features include a trailer, and park brake (see comments on the Scania).

First impressions of the Steyr 19531 cab is tht it is very much like the old pre-95 Series Daf Space cab not that that's anything to be ashamed of, for the old Daf high-roof tractors were certainly popular with large fleet operators and owner-drivers alike.

The dark-and-light-brown trim is best described as workmanlike and is unlikely to show the dirt; the rubber floor covering also looks easy to sweep out.

Clambering over the high centre engine hump and console is a bit of a strain, as is the climb into the top bunk which can best be likened to the old-fashioned straddle highjump manoeuvre. The curtains close easily round the windows, and there is even a separate set for the top bunk, making it even cosier. The actual material is a bit like sacking but it does the job, as does the block of fabric-covered foam which serves as a pillow. The bunk itself gave plenty of support.

The only problem with being in the top sleeper is that you can't sit up so it does feel rather claustrophobic at times and a full size roof vent big enough to crawl out of would be appreciated. No doubt you soon get used to it if you do have to use both bunks. There are two safety straps to stop the driver from rolling out of the top bunk.

There was no doubting the effectiveness of the heater either it raised the Steyr's inside temperature to a warm 21W within 22 minutes, but it was noticeable how fast it cooled down once the heater was switched off for the night.

Come the morning our tester felt fully refreshed. Any driver spending a long time away from home in his truck will appreciate the Steyr's spacious cab, but next time we'll make more use of the heater and opt for the extra room of the bottom berth.

Volvo F16-20 Globetrotter

The thing that operators have been talking about when it comes to the F16 is not its towering Globetrotter cab, but the mighty TD162F 334kW (456hp) 16-litre engine which, launched in October 1987, took Volvo well and truly into the 298kW (400hp)-plus, high-power truck sector.

While the TD 162F has been on the market for less than two years, the same cannot be said of the F16's cab. Its roots stretch back to the middle of 1977, when the first F10/12 models made their debut at the Frankfurt Show. The optional highroof Globetrotter cab, some 370mm higher than the conventional F cab roof line, came along three years later when there was still plenty of long-haul TIR business running to the Middle East to justify the purchase.

When CM drove one of the first F12 Globetrotters back in 1980 we reckoned that the cab's unique self-levelling system was so good that "perhaps Volvo should consider fitting it as standard". So far, however, it is still unique to the Globetrotter.

Apart from the odd bit of fine-tuning, like the adoption of a slightly higher curving roof line on the standard cab in the mid-eighties, the basic F cab has changed tittle. The last significant revisions coincided with the launch of the F16 and the reworked 10 and 12-litre engines when it gained square headlights within a facelifted front end.

The cab suspension was also revised with link-type trailing arms fitted at the front to improve comfort.

The Globetrotter cab, listed as available on the F12/16 and as a special order on the F10, has a conventional suspension system with coil springs and dampers on the front along with a torsion bar. At the back there are more coil springs, but the dampers also have a built in air-operated self-levelling device which compensates for any backward lean of the cab caused by heavy equipment, acceleration forces or luggage. The levelling pressure is provided by a valve which senses cab rake. Only the Globetrotter version of the F cab enjoys this system.

Over the years Volvo has regularly tweaked the interior of the F cab, but look hard and it's not difficult to see bits of the original design peeking through, albeit under a different colour trim. The fascia is a straight-across affair, with none of the ergonomic curve found in its FL10 stablemate. Volvo isn't a great one for giving away advanced product details, but don't be surprised if a revised interior appears fairly soon.

Despite its rather sombre interior

there's no doubting the Globetrotter's pedigree. Standard features include a single bunk (our sleeper had two); Isringhausen air-suspension driver's seat; twin fog lights; headlamp wipers; full airconditioning; electric windows; tinted glass and a fully-adjustable steering wheel. You'll have to pay £499.82 for an Ebers

pacher night heater, however, which is the kind of thing that one would expect to be standard. You'll also have to shell out extra if you want a radio.

The F16 Globetrotter cab is an all steel construction built to the demanding Swedish safety regulations, and is covered by a three-year anti-corrosion warranty, subject to the usual inspections.

Climbing up into Volvo's lofty F16 cab is not something to be taken lightly: there are three steep steps to be overcome — the bottom one at 525mrn being the highest in our test sample — before the driver is able to get behind the wheel.

Once seated, however, the F16's roomy cab is much more hospitable, being warmly trimmed out in a mixture of greys, and though the cab heater outlet fouled against the backrest, the seats are fully adjustable. With steering wheel height and rake adjustment too, most drivers can be accommodated.

From the driver's lofty perch there are commanding views of life below, broken only by the 125mm blind spots of the A-posts.

Lighting switches are large and well-lit, while gauges are clearly marked and easily seen through the car-like steering wheel, (although some of the warning lights along the top of the panel are obscured).

Two stalk switches on the left of the wheel control the indicators and windscreen wipers: but the latter partially obscured the speedo. The exhaust button is sited more usefully behind the column for toe operation.

Cab temperature can be finely tuned, although the controls are a good stretch away in the centre of the dash, and there are fresh-air vents to serve the driver when needed.

Movement between the seats is wellnigh impossible, but once the driver moves around in preparation for bedding down, the 1.97m of standing room in the footwell is more than adequate to make changing clothes a comfortable task.

Mind you, extreme care is needed when drawing the curtains as the flimsy plastic hooks holding them in place fall off and dive down the demister vents quicker than rats down a drainpipe.

The driver's door top panel is very flexible and feels insecure. Several screws in the centre panel were loose. The cab walls look very deeply insulated and both bunks are fairly long, and warmly covered.

The lower one, at 125mm deep, is very comfortable for an over-night; the top bunk, at 75mm, less so. When not in use the only apparent way to secure it against the rear wall is with its straps, which is very untidy.

There are useful elasticated pockets on the rear bulkhead for reading matter, and two levels of lighting. The bottom sleeper has soft, rather dim lights, while his upstairs neighbour has glaring strip lamps to

complement the small lights above the doorway. Full marks for Volvo's excellent radio/cassette player, but being set into the header rail it is a long reach from the bottom bunk when the driver decides to turn in. A remote on/off button would help.

From the ambient temperature the Eberspacher blew cold for five minutes then took half an hour to bring the cab up to 21°C. Better routeing of the ducting would have helped; at present it pumps the warm air flow under the seat and the front panel.

Volvo equips the cab with a hanging bag for clothing and there is a large storage space behind each seat. The one on the driver's side opens from the outside and is suitable for tools and so on, while the other is right for personal belongings — it's a pity that using it entails shifting the seat forward or raising the bottom bunk with all the complications that entails.

RIDE COMFORT

• Examining the ride quality of each of the seven vehicles under scrutiny required more than our standard road test equipment, so with MIRA's help and the use of its sophisticated 909-1 Ridemeter we measured the G-forces acting on the driver. It is one of only half a dozen purposemade recorders which have been produced for clients in America, Europe and the Far East.

In our tests, with each vehicle driven at a constant 32km/h along the same stretch of broken-concrete track, sensors on the driver's seat and on the cab floor measured vertical acceleration forces as well as horizontal forces through the backrest. The results shown in the table are averages, taken over the set distance of track.

As we had to use a different piece of road to that used in last year's cab test (CM 18-24 February 1988) the two sets of results can not be directly compared.

Although all seven cabs have air-sprung seats, there are other considerable differences between them such as axle configurations, wheelbase, chassis and cab suspension. These should be borne in mind when comparing ride results.

Clearly the Strato's sophisticated fourpoint pneumatic cab suspension, like that of the Scania R143, pays dividends, by recording the lowest vertical forces of them all. Both showed extremely good recovery over the worst ground, but whereas the Strato let itself down with clacking bumpy noises rumbling from the front spring area, the big Swede was far quieter.

As far as the seat performances go, all worked extremely hard, taking between 22 and 36% of the upward thrust away from the driver, with the Renault's working hardest of all. This, for those drivers who suffer silently with backaches, will come as a welcome relief. The suspension seat in Seddon Atkinson's Strato did very little: its vertical forces were only 6.0% better than those rising through the floor.

There was little to choose between the two most rigid cabs — the Roadtrain 17.28 and Steyr's 19S31 both allow considerable upwards reaction (0.209g and 0.185g respectively). The 17.28 was more like a bucking bronco over the worst bit, preventing any control over the accelerator pedal.

Steyr's elder statesman was not quite as bad, but was noisy, bounced quite a bit and took longer to recover over the worst potholes.

Rather surprisingly, Renault's twinsteer, which felt very smooth over the rough, recorded rather middle-of-the-road figures of 0.161g, with the Mercedes 1729's 0.153g, not so far behind. Volvo's F16 emitted squeaks and crackles from the vicinity of the dash and door panels over the worst surfaces, but there was very little bounce and it was possible to control the accelerator.

INSULATION

As well as keeping Jack Frost out, a cab's insulation must be capable of withstanding the racket from a noisy refrigeration unit when it clatters into life alongside a truck parked during rest periods or when preparing for an overnight.

We tested this theory by parking each of the seven under scrutiny just 1.8m (71in) from a noisy Perkins-engined compressor which produced 88dB(A), measured at the outside of the driver's door.

Readings taken inside the cabs showed that without exception more noise filters in from outside than rises from the trucks' own engine on tickover, which is a bad deal for a tired driver trying to rest and recharge his mental and physical batteries for the day ahead.

The two Swedish cabs proved to have the best insulation, with the Renault and the Strato close behind them. But oddly the Roadtrain was top of the heat insulation stakes, warming up to 21°C within 14 minutes on a night that was not as cold as expected when we planned the event late last year.

The Scania and Steyr came next, at 20 and 24 minutes, with the Mercedes-Benz 1729, Strato and F16-20 all around the 40-minute mark.

The unfortunate driver inside Renault's R365-22TD cab had the longest wait (an hour) and, like most of the others, it could only hold out to 7.0°C against a minimum ambient of 5.6°C.

Scania's big R143MA sleeper seems to give the best value as far as the driver's welfare is concerned: it warmed up fast and held its overnight temperature to 11°C. Seddon Atkinson's Strato cab held in 9.0°C of warmth, with the Volvo F16 one degree lower.