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By Road and Rail?
CygnusXII writes "Now this is a novel approach to Dual Mode Transportation. This is an interesting and refreshing approach, that could revolutionize the transportation industry. BladeRunner Dual Mode Transport, or see the main web page. The innovative vehicle will run on road as well as rail. It is as applicable to freight as to passenger transport. Branch-line infrastructure costs could be at least halved because signalling and points could be largely, if not totally, made redundant."
Takes out most rail infrastructure cost
I guess this is the main reason. I guess it's designed mostly not for human transport, it's for freight. And a crate does not get off the train and attaches itself to a truck all by itself...
Neat idea, I hope someone will feel like putting some $$ in.
Paaul B.
If you read the site, they note that there have been previous solutions that do exactly what they're trying to do here. The advantage they claim is that their design doesn't attempt to power the rail wheels, and instead uses the main tires to provide power and braking. They say that this results in a significant cost savings.
There's also what appears to be some clever design work which allows the operator to reduce the amount of weight placed on the tires to increase fuel efficiency while cruising, but then rapidly change the weight distribution so as to press down hard while braking.
A good rule of thumb for stopping distance is roughly 1 meter per kph in daytime, about 1 1/4 at night; I've heard that at 80kph (which is exactly 50mph for those of us in the States) the distance is about 81 meters (about 245 feet) and at night it's about 95m (about 300 feet).
Not a chance. You don't know anything about railroads, do you? They already thought of this.
Every railroad operates on a "block" system. This is an interlock designed so that only one rail vehicle may enter an area of track at a time. At the start of each block is a red / green signal and either a speed limit sign or an automated transponder to tell the operator the maximum speed limit for the block they are about to enter. The area of a signal block is something large enough for a train to come to a complete stop, or if necessary, when a train enters a track the signal for the block it is in and the block before it (to allow for any train following it) become red. The faster trains run in an area the larger the block is (or the more preceding blocks are also interlocked). Once a train enters a block, the signal behind it at the entrance to that block turns red and stays red until they enter a new block or change to a different track. It may also cause the transponder in the block behind it to order approaching trains to reduce speed in case they get to their block before they are clear so that they won't have trouble slowing down if necessary. Only once it is completely clear of a block will the signal for that block turn green again. A train operator who sees a red signal will stop their train and not enter the block until it turns green, same as you will stop at a red light when operating a motor vehicle on a street.
An automated train will warn the operator that the next block is occupied and if he fails to bring the train to a stop and crosses the red signal anyway, it will trip the emergency brakes and the train slams to a stop. This is why it's said when a rail engineer runs a red signal he "tripped a signal." If the engineer enters a block at a speed faster than the transponder it will either apply braking or give a warning then trip. The rail system is designed to prevent this sort of thing from happening. This system is also in place in the event of rail fissures, there is a small electrical current running along the rail, if any rail comes loose, it breaks the connection and turns the block red so a train can't enter it, or possibly opens an earlier switch so trains can be routed around the block, I'm not exactly sure.
I do know that rail systems are specifically designed to prevent this sort of thing in the absence of negligence or intentional misconduct. If a train operator ignores signals in some cases they may be able to run red lights (on non-automated trains) but the scenario you describe can't happen except by intentional misconduct or flagrant negligence. Besides that
The lessons of history teach us - if they teach us anything - that nobody learns the lessons that history teaches us.
The modern implementation of TOFC started in the mid-1950's - special flats cars were being built in the early 1960's (often owned by Trailer-Train) - the earliest implementation dates back to about 1920, didn't take off then because of opposition from the state highway authorities (trucks were avoiding road use fees).
For long hauls - it makes more sense just to use the box (i.e. containers) - as it reduces weight and air resistance. The Espee pioneered double-stacks (i.e. stacking two containers on one car) with articulated car-sets to further reduce tare weight and train length (single stack trains were too long for the sidings).
To answer your question - the onde advantage of this approach over TOFC is that you can have much smaller trains.
A Shadeless room is a brighter room.
This is certainly not new news. Similar vehicles were in use in the 1960s in Germany. The whole concept of putting a bus on rails, i.e. building a light-weight DMU with bus components, isn't exactly new either..
The stopping distances quoted above are for automobiles on dry pavement. Trains take quote a bit more distance
150-car freight train stopping distance
30 mph =3,500 feet or 2/3 of a mile
50 mph =8,000 feet or 1 1/2 miles
8-car passenger train stopping distance
60 mph =3,500 feet or 2/3 of a mile
79 mph =6,000 feet or 1 1/8 miles
(Data from various Operation Lifesaver websites...)