Monday, 26 November 2007

60tonne "Superlorry"

So the DoT is considering a trial of superlorries of 60 tonnes and two linked containers.

Reasons are lower costs and lower emmissions.

Lower direct costs for the hauliers, I suppose - less labour.

Considering a 38-tonnne truck does 10,000 times more damage than a 1-tonne car, I do not see HGVs now paying their way.

If the aim of the scheme is to lower emissions by linking two containers together, that gives me an idea...

How about linking a whole string together so one driver could pull a multitude? How about making them run on special roads thatcan take such weights? Make the road and the wheels low friction but still able to take the weight and provide sufficient traction? How about making the roads dedicated and direct, so no risk of collisions from private vehicles or delays due to traffic etc.? If we use special computer management, we could even do without the driver when on the dedicated route, as computer control could keep each string of containers separate from each other. In case of failure, the part-time driver could know if the way ahead is clear by using a form of traffic lights as a fall-back system. That would be even more energy efficient.

I know what, lets call it a "railway"?


Phil A said...

I have advocated a return of freight to the rail network before, so I agree with the thrust of your argument.

Re the linked trailers. I think much of the damage a vehicle does is the actual weight being carried by each wheel and hence the force impacting on the road surface at the pint of contact with the wheel. Splitting the load between two trailers would reduce that.

Roger Thornhill said...

Reduce is no the term - we are still significantly increasing (40%) the damage an HGV does. Considering it is doing 10,000 more damage than a car in 38tonne mode, then I would say 14,000 times more damage in 60tonne mode.

If you subsidise rail freight to the extent of road, we would see more rail (which can then be used for commuter use for peak travel and freight for the rest)

Roger Thornhill said...

p.s. but the idea is you subsidise neither and let the market pick the best way.

Phil A said...

Roger, Re damage. What I was pointing out is that if you split a load into two trailers it is as if it were two smaller trucks.

A significant factor in the amount of damage a vehicle does to a road surface is the total force the weight of the vehicle, as distributed via the wheels, imparts to the road surface.

I believe the number of driving wheels also makes a difference.

If you have two linked 30 tonne trailers that will be roughly the equivalent of two 30 tonne trucks, not the same as a 38 tonne truck.

Assuming a notional 6 wheels per truck, or trailer, the trailers will only impart a force of 5 tonnes on any one point on the road as opposed to 6.3 tonnes for the single 38 tonne truck.

Re therail network. I agree ideally the market would decide. I do worry that it is distorted though by Government policy, rules, regulations and mishandling of the rail network over the years.

Roger Thornhill said...

Indeed, Phil, that is what I understood. Maybe we tax the tractor unit and then tax each 30tonne trailer accordingly, so double if they tow two units.

Unfortunately, we will just get more calls for road widening and see more cyclists crushed as we do with bendy buses.

Removal of distortions will create a better system and this includes the planning process to enable new freight lines to be built.

Phil A said...

Roger, Trailers may be vehicles, but not motor vehicles, so should not attract road tax on their own. Bad precedent to allow tax to be increased worse if applied to something new.

Roger Thornhill said...

If said trailer is doing 10,000x the damage of a 1 tonne car, then something needs to be sorted.

Paying for use or State subsidy?

Maybe private cars are paying too much...erm, yes they are!...but on balance haulage is not paying for their share of the infrastructure use AFAICT. To allow 60tonne vehicles with no recognition for the doubling of damage vs a 38tonner is just entrenching the distortion.

Phil A said...

To paraphrase Marx. “All taxation is theft”.

Having said that, if you are going to (allegedly - what have they done with it?) fund roads by some sort of vehicle/fuel tax then is should be transparent and based on the maximum weight carried by each wheel, the number of wheels and the fuel used.

I would still dispute that the damage is actually doubled with trailered vehicles as you are not increasing the load each wheel carries.

Roger Thornhill said...

phil, it will be doubled, because there will be twice as many axles and wheels - it will seem to the road like two vehicles are passing along the road very close together.

Yes, it should be transparent. I would like the same for vehicles - sod the CO2 nonsense - use fuel tax if you must, but vehicle weight and area (i.e. the space they use up).

Phil A said...

Roger, Re “there will be twice as many axles and wheels - it will seem to the road like two vehicles are passing along the road very close together.”

Yes, exactly. I entirely agree - but it does not follow this will necessarily double the damage, as the wheels will individually be imparting less force to the road surface, even though it is twice as often.

You are looking at the difference between one 38 tonne truck and two 30 tonne trucks. Certainly two 30 tonne trucks will do more damage than one 30 tonne truck, but the pair together may not do as much as a singe 38 tonne truck.

Think of the damage…

Warning the argument coming up may be interpreted by some a sexist. Anyone who thinks they are likely to be offended are advised to stop reading now!

…a pair of stiletto heels worn by a nine stone woman can do to a floor compared to flat heels worn by an 18 stone man. The relevant factor is how much force is concentrated into what size area.

I was using fuel consumed, as it is a good rule of thumb measure, combining distance travelled and weight carried. It would also be acceptable to the anthropocentric global warming believers and environ-Mentalists.

Given the proportion of the cost of fuel taken up in taxation and the amount of revenue taken as a result, if fuel tax were only used to support road building, maintenance, renewal, and traffic police I would expect the cost of fuel to drop.

Roger Thornhill said...

I agree it all depends on the axle config, but everything being equal, a 38tonner is most likely to do less damage than a 60tonner.

A typical 38tonner is 3 axles on the tractor and two on the trailer, with some of the load on the 2 rear tractor axles. I would suspect that the additional trailer would have 2 or 3 axles.