Blade Runner Dualmode System

by Carl Henderson


An overview article about Blade Runner was published in Bus and Coach Buyer, June '04, and is available by clicking here.  Also, an updated summary is now available. Also, see the official Blade Runner website for the
most current information on this concept.


Maximising the benefits and avoiding the problems of road and rail.

It is not the roads that can not cope with the traffic, it is the drivers.

It is not the rail lines that are running to capacity, it is the network of crossing points.

"Railways are environmentally friendly - who can argue with that? Trains, travelling at moderate speeds on gently sloping, low-friction tracks, are an energy efficient way to transport large loads over long distances. But, unlike trucks, they are inflexible and they involve enormous capital costs..." - Commercial Motor (23 Dec 99 - 12 Jan 00)

The rolling resistance of metal wheels running on metal tracks is a tenth that of rubber on tarmac and with the aerodynamic drag of one front and one rear of a train shared among say ten carriages, rail should be significantly more efficient than road. But it is not! Also a major down side of using metal on metal, compared to rubber on tarmac, is that it takes just a little lubrication to create a very effective bearing. Problems then arise when you want to get a 1500 tonne train moving without burning the tracks, or stopping it again in a hurry. Train protection systems, advanced or otherwise, can only apply the brakes, physics dictates whether the train will stop in time or not and the fact that trains can run head to head for a time while they cross defines the scale of a collision.

Railways can be efficient at moving groups of passengers quickly and quietly, covering long distances with only a few stops. As such they would provide a sustainable alternative to short haul aeroplane flights and help reduce airport congestion. Instead, slower freight and commuter traffic also use the main lines, stopping whole trains to pick-up or set-down just a few passengers, eating away at the potential fuel savings and congesting the network.

Take freight. Much of the freight moved around the country runs to cube (billion.m3.km) and not to gross (billion.tonne.km) as the DETR figures would suggest. Compare an articulated lorry load (26 pallets) of Yorkshire Puddings, which weighs only 2.75 tonnes, with a similar lorry load of say Baked beans weighing 26 tonne. Not so obvious is the fact that both vehicles create the same amount of congestion. When you transfer these two vehicles on to rail, you add another
25-30 tonne rail carriage as ballast to each consignment. Rolling resistance is in proportion to the load on the wheels. By doubling the load, you double the drag and so halve the efficiency gain.

Now take these loads and add a mere ten mile detour and a ten minute delay, at each end of a piggy back rail journey. And even if the freight train could average 80 mph between interchange centres, it would still take a haul distance of over 160 miles for the loads to arrive at the same time as another load that continued on the main road at 60mph. The current domestic average haul distance is 56 miles (DETR figures) and with improvements in logistics and communication, this average is likely to fall as more pickups and deliveries are made per journey. The extended haul distance to and from the railheads, the increased vehicle speeds and the running of the loading equipment further detracts from the sustainability of rail freight. Run the rail carriages back empty and you have more than lost any environmental benefit.

Improved service. If it were possible for a train operator to split all of their trains and run the separate carriages ten times as frequent, a 30-minute service could become a 3-minute service. Soon a point is reached where the need for timetables is diminished. Unfortunately trains will always need timetables, or more precisely, trains will need to be timed to miss each other as they cross lines or stop at stations and accidents will continue to be caused by people having to rush to catch them. So forget the existing railways and take another look at our roads.

A road-rail hybrid system.

webDualmode rail.jpg (149301 bytes)Just-in-time manufacturing requires Just-in-time transportation. Commuter passengers would also appreciate predictable journey times, with no more early starts and late arrivals. I suggest we need to create a safe and reliable 'hybrid' system that is also very efficient, maintains spare capacity and is freely accessible. A hybrid system could be created by running vehicles on rail lines without the junctions and stations of the railways, but with the braking performance and flexibility of road vehicles. Narrow designated lanes, with rail lines embedded into the pavement, would run down the centre of every trunk road in the country and form the basic infrastructure for a very efficient transport alternative.

By moving a large proportion of the lorries and buses over into these lanes, we would help clear the inner lanes making them safer for the remaining cars and vans. In return, priority would have to be given to these larger vehicles crossing the inner feeder lanes near junctions. Once in the dual-mode system, the vehicles would lower their air suspension and transfer load onto sets of rail wheels mounted to their chassis. As with the railways, the power requirement would then drop from say 300kW down to 230kW, due to the reduced tyre drag. Inter-vehicle communication and adaptive cruise control (ACC) would group vehicles into short efficient convoys, taking the fuel consumption form 9 mpg up to 11.5 mpg.

Using Existing Technology. Brake-by-wire and steer-by-wire are already available, but there are current legal issues, relating to the liability for accidents actually caused by only some vehicles having the enhanced braking performance. Both the accidents and the liability can be avoided by creating designated telematic lanes. Now all the vehicles in these lanes could be electronically coupled into short convoys, which would brake and move as one. By keeping the headway to a minimum (say 0.2 metre) the closing velocity, if any vehicle has a total systems failure, is minimal. A simple mechanical coupling would enable a faulty vehicle to be guided off the system when it was convenient.

Junctions. With all junctions being on the existing road network, stacking areas would have to be created to accommodate for any initial exit or lane congestion. Vehicles would continue on to these parks and wait a predefined time for an allocated slot, similar to the ramp metering schemes now being tried on some motorways. With onboard diagnostics, any defective vehicles would not be accepted onto the system, but would have to complete their journey by road.

System management. Radio and infrared communication between vehicles and via beacons alongside the roads would relay any incident across a number of different networks to the system controllers and emergency services. Diversions and lane speeds could be modified to adapt to local conditions and the performance of the system continually monitored to plan for changes in throughput. At night, much of the system could run at half speed, reducing noise and promoting sleeper services and the very efficient ‘trunking’ of freight. While speeds are reduced, lane sweeping and surveying operations could be done without even closing a section. As many of the heavily loaded axles would be transferred on to the 'rail-lanes', linear quarrying (lifting and relaying the tarmac) could be used to gradually improve the quality of the roads. The dual-mode traffic could also, if necessary, be switched to run down the main road while sections of rail-lane are closed for more major repairs.

Throughput. A railway line can cope with a large train every five or ten minutes. A road lane can accommodate a car every two seconds, whatever the speed. With say six hundred passengers on the train or two people in each car the throughput in both cases is one or two people per second. A dual-mode system, on the other hand, could carry seventy passengers per vehicle, running in convoys of ten vehicles and allowing plenty of room for other vehicles to join or

leave the system. Say just two convoys per kilometre running at 100 km/h (62 mph), the system would easily transport nearly forty passengers per second, a twenty fold increase over either of the existing road or rail networks. Construct two narrow dual mode lanes along very busy stretches and you have the spare capacity to allow for major repairs, without jeopardising service. Also the argument for the land taken up by rail compared to that of road is not so clear cut when you consider the relative throughputs.

What will it cost? Concrete is about 80/cubic metre compared to 90/cubic metre for black top and rail line is about 20/metre. So to slip form a concrete lane, fix the rail lines and in-fill with black top would cost ~250k/km. Add on planning and red tape and a figure of about 600k to 1m/km is more likely. There are currently about 15,000 km of motorways and major trunk roads in the UK and 25 slip-forming machines each capable of forming 50 metres of pavement per hour. Allowing a slight discount for bulk, it will cost 7.5 billion each way, 15 billion in total, for the complete dual-mode network. The 3,000 km motorway network could similarly be constructed for a 1 billion per year and completed in just three years.

Alternatively, what will it cost the country to strengthen the hundreds of bridges and enlarge all our tunnels so that the existing rail network can cope with rail freight at a combined weight of 70 tonne per rail carriage and a height of over 5 metres?

Bus and lorry conversions. A modular swap bogie design would give outstanding stability, comfort and flexibility. Existing coaches and lorries could be converted and new vehicles designed with bogies at the front and the rear of the chassis. This would provide the space for 36 low-floor seats, twice that of even the larger articulated buses or even enough room to sleep comfortably. Initially running on diesel-electric they avoid the need for unsightly over-head cables and the associated transmission losses, while catering for regenerative braking.

It is expected that the additional cost for the dual-mode capability will be between 35k - 50k. At around 3500 per seat, a dual-mode coach would be half the cost of a car and a quarter that of a train, per seat. Assuming that 80% of any journey can be done on the 'rail-lanes', the overall fuel consumption would be improved by 2 mpg. For a lorry that travels 90,000 miles each year, averaging 9 miles per gallon (3.5 / gallon), the haulier would save over 20% of his yearly fuel bill, contributing 7,600 to the additional cost of the vehicle and providing a 4.5 year payback on fuel savings alone.

Rural areas. We now have a great opportunity to revive much of the disused railway, and its surrounding area. A new dual-mode system would pass quietly along in the line of the old tracks, at speeds more in keeping with its surroundings. Slower than the main routes, but still with predictable journey times. Villages along the route would have the opportunity to offer services to attract the passing travellers, revitalising remote regions without congesting the country lanes. The actual speed of the system could be set locally. Too slow and much of the needed trade would choose alternative routes, too fast and few may stop. Once again these communities could take pride in their rail system. Slip lanes leading away from the rail-lanes near the old train stations and merging again beyond them would provide access to the system. As none of the vehicles on the new system will ever stop on the rail-lane itself, other than in an emergency, through traffic would just keep on going.

City centres. Interchange centres, outside the main cities, would allow passengers to swap from other modes of transport onto the dual-mode town vehicles. With designated bus lanes in and around the centre, rail lines could encircle the city like a snakes and ladders board, passengers and cargo would be ferried efficiently in and out of the city, while small delivery vehicles run back and forth delivering shopping and picking up internet orders. Some vehicles, corporate or service, with a park or an off loading bay in the city, could travel freely from one city to another, from one door to another. Meetings could be held on the move, in mobile boardrooms or restaurants and the entire journey time could be used constructively, rather than wasted, waiting on platforms or swapping between vehicles.

Bulk freight. It may seem unlikely that this dual-mode system could challenge rail at moving thousands of tonnes of coal a week to a Power station or limestone from a quarry to the steel works. But why not use the system like a conveyor, moving just a wagonload an hour, directly into the feed hoppers. Merge these vehicles with all the others and you have a high priority, very controllable alternative to the train with significant reductions in the handling overheads. Some of these dual-mode lanes may not need feeder lanes along their full length due to their remoteness or nature.

 


Next step. We have already built a concept freight trailer that demonstrates how sustainability can be made commercially viable. This vehicle has the same overall length as a wagon and drawbar trailer, but with a fully steered pivotal bogie at the rear. Not only is it more stable and safer than a standard trailer, it can carry 17.5% more volume while still driving around in a narrower corridor, with less cut-in and less swing-out, reducing the number of vehicles on the road and improving traffic flow. The fully steered bogie also triples tyre life and reduces fuel consumption and road damage. Once the rear of the vehicle follows in the tracks of the front, it is straightforward to lower the suspension and transfer on to rail lines. Our next step is to build two dual-mode vehicles for use by a rural railway association.

Europe. To plan a dual-mode journey across Europe, all that would be needed is the various line speeds along the route and possibly the line tolls. Unfortunately Europe is currently too busy harmonising vehicle limitations to properly consider new concepts. It is also promoting ‘inter-modality’ and ‘freight on rail’ as the solutions for sustainable transport, solely on the basis that the road corridors can not cope. New legislation is urgently needed if we are to stop the subsidising of inappropriate design and open the market to new ideas.

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Distributed control.

A haulier is able to balance the needs of his drivers with the efficient running of his fleet. With the freedom to adjust the schedule of his vehicles throughout the day, he is able to maximise their performance and cut waste. Both the route and the drops may well be in flux until the last minute. If he needs to, he can call a vehicle in for service or to change drivers mid shift. All this flexibility is lost as soon as he tries to build a rail journey into a trip. Days can be wasted waiting in queues or by missed connections, leaving lorries stuck with loads they can not tip. Trains leave half-empty but on time, sometimes just to sit and wait further up the track, wasteful and inconvenient.

Appropriate technology. Railway interchange centres are hub networks that are well understood and relatively easy to build and explain. They are an ideal system to move large numbers of very small items quickly and efficiently, when the investment in infrastructure is high. In fact the system is only ever truly efficient when the extended journey time is minimal and the wasted energy is negligible. (A few good examples are the body’s nervous system and the telephone exchange, where central control is of benefit. Electrons, travelling at the speed of light are switched in the hubs to efficiently negotiate the network). In all other cases, nature has selected a continuous flow or a circulation (or hybrid dual-mode) system because it is the most efficient and reliable means to transport sustenance, waste and chemical messages, in, out and around a body (or country), decentralised and resilient.

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For the above journey from A to B to sensibly include a section on the efficient rail network, direct access to the rail lines (veins) between stations is necessary. This can not be done within the existing railway structure.

Roads make up the arterial routes of the country, not the railways.

Railway interchange centres are definitely not the solution to our transport problems. They must be either large and unwieldy, like out of town shopping centres, detracting from the cities they are meant to serve or small and numerous, like villages with large car parks, where commuters and cargo are perpetually moved between vehicles or stand waiting on the platforms.

Every journey via a hub or station will inevitably be longer in both time and distance than it need be, increasing the volume of traffic on the move at any one time. Hubs, like stations, are also ideal targets for disruption, potentially crippling the network and endangering the public. As such it will remain an aspiration to be able to afford not to have to use public transport. Escalating taxes, higher insurance premiums and the introduction of road tolls may eventually push many more of us into the drudgery that is set to be our future transport.

We must start to invest in a more resilient transport system!

Unless the case for a hybrid transport system and a distributed control network is made clearly, the Highways Agency will push ahead with their thirty-year plan and promote these interchange centres (transport hubs) and subsidised railways. We will then be committing another generation to the hassle, inefficiency and pollution we have all had to endure.

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Dualmode is a concept that can deliver.

Click here for more illustrations of this concept.

See a description of an evolutionary, four-step deployment plan

Also see the Update and Slide Show, July, 2004

For the latest information, see the official Blade Runner website.


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Last modified: February 18, 2006