Automotive History: The First Articulated Buses – 1938 Twin Coach and 1940 Isotta Fraschini TS40

Sleuthing out who built the first of any new significant automotive development can be a fraught undertaking. When I wrote up the remarkable 1946 Kaiser articulated bus, I really thought it was the first of its kind. Well, in some ways it still is, in terms of an IC engine powered highway coach. But there were two previous pioneers of the articulated bus, for transit use. Somewhat oddly though, the first one, the 1938 Twin Coach (above) was only articulated vertically. But in another (presumably) pioneering way, it had a diesel-electric propulsion system, which of course made it also very suitable to be used as a trolley-bus with overhead lines, or to operate in either configuration.

As to the first fully articulated bus, it appears to be the Italian Isotta Fraschini TS40. More on that further down.

Let’s first take a look at this remarkable invention by Fageol, at their Twin Coach division. In the 1930s, during the Depression, there was a need for relatively low-cost transit solutions that didn’t require laying more expensive track. I’m going to just copy the twin Coach press release from 1938, via coachbuilt.com:

“Kent, Ohio, June 15—The largest, capacity passenger vehicle for public carrier service, without the use of tracks, has been announced this month by Frank R. and William B. Fageol, President and Vice President, respectively, of the Twin Coach Company of this city. The vehicle seats 58 passengers on a single deck, and will transport readily, a passenger load of 120, including standees. The unit is designed to operate as an electric trolley coach or by Diesel-electric propulsion. The vehicle has four axles, eight wheels and bears its lead on 12 tires, the four center wheels taking dual rubber equipment. It weighs 27,500 pounds and is known as the Super-Twin.

“This unit will be capable of 50 miles per hour top speed, and, therefore, in regular schedule traffic, should have no difficulty in maintaining average schedule speed of 13 to 14 miles per hour, which is within one or two miles per hour of the average speed on principal subway lines.

apparently there were both three and four axle versions

“The new vehicle, on the fiftieth anniversary of the operation of electric trolley cars operating upon steel rails in the United States, immediately becomes a threat to continued large city street car operation, because it is the first seemingly practical unit created as a rubber tired public carrier capable of equaling the capacity of the largest city street cars, and at the same time, being able to turn on a radius no greater than the many 35-passenger gasoline coaches already in service in great numbers in this country. This is done by means of the synchronous steering of the front and rear wheels. The four wheels at the center of the job operate on the principle adapted to the many six-wheel vehicles already in use.

this is a later version, but it shows how it was articulated vertically

“Because of its 47 foot length, the body is hinged perpendicularly at the center, and the space covered by a newly developed flexible rubber hood, the perpendicular articulation allowing it to take with ease, bridge, viaduct and other sharp grades oftentimes found within the confines of the metropolitan area. There is no horizontal articulation and the width of the vehicle may be made to equal that of the large capacity trolley cars. The floor has no obstructions of any kind.

“As in a trackless trolley coach, the propulsion is through two 125-horse-power electrical motors placed under the floor of each body unit and driving into the two center axles. The first vehicle for practical demonstrating purposes is a Diesel-Electric vehicle with 175-horsepower Hercules Diesel motor with electric generator in the rear compartment, supplying current to the two electric motors located under the floor adjacent to the two center axles. The electrical equipment has been supplied by General Electric Company.

“The oil-electric propulsion equipment is generally the same as that used to run the Diesel-Electric Zephyr and other crack high speed transcontinental trains. It is much easier for the operator to handle than the ordinary bus on account of the simplicity of controls which consist of a reversing lever to get forward and reverse directions and a foot accelerating pedal which operates the same as your automobile. As you press the pedal down it adds more fuel to the Diesel motor, thereby causing the motor to revolve at higher speed and it being connected to the electric generator, there is an immediate increase of motive power from the generator to the motor. In other words, the action on the propulsion motor, when the fuel accelerator is pushed down, is similar to the result when the motorman on a street car turns his controller around. The further he goes with the handle, the more electricity is put in the motors and thus the increase in speed.

“The Diesel motor differs from the gas motor in that it has no spark plugs, therefore, no electric ignition. The fuel used is what is known as distillate or oil similar to that used in oil furnaces.

“The ignition of the fuel is brought about by high compression temperatures and through properly governed and timed oil injection into the cylinders.

“The springing of the job is taken care of by a newly designed type of cantilever spring giving the rider the impression of that of a boat rather than the short, quick impacts of urban rail transportation.

“Control of the new vehicle by the operator is exactly the same as on a conventional motor coach or trolley coach. The steering of the front and rear wheels is accomplished through linkage and the use of air which automatically supplements the manual effort on the driver’s wheel, and trolley buses are in use on urban operating systems, a complete transition to rubber tired vehicles has been held back by the lack of a tired unit capable of carrying as many as a large trolley car. This has been due to inability to produce a trackless vehicle of that size capable of making the necessary street intersection turns.

“It will be recalled it was the Fageol Brothers, who, in 1927, introduced the first transit or metropolitan type gas coach, namely, the box type body with motors inside instead of under the hood as in the old type vehicle. That style of design, in the past ten years, has become universally adopted on major operations.

“Some idea of the significance of this new Fageol development may be gained by such economic facts as the following, pointed out by Ross Schram, Sales Manager for the manufacturer:

1. According to the statistical record of TRANSIT JOURNAL, there were 75,777 urban public carrier vehicles in use December 31st, 1937, and 34,190 of these were street cars, mostly of the large capacity size, while many of the 25,614 motor coaches would have been purchased in larger capacity had there been an available unit.

2. Modern trolley car road bed and track cost per mile is $100,000 for double tracks.

3. The average expenditure per mile for trolley car road-way maintenance in American cities during normal times is 3½ cents per mile.

4. The reduction of fuel cost over gasoline, if Diesel-Electric power plant is adopted.

5. Tremendous sums and engineering efforts have been focused on the development of a new automatic transmission for large trackless gasoline units with questionable results thus far. In this new unit, as in other trolley coaches and Diesel Electric vehicles, there is immediately available the perfect answer to this quest.

6. The large capacity rubber tired trackless ‘street car’ of this type is no longer tied to a strip in the center of the street, and thus traffic weaving, the greatest of all street hazards, should be reduced to a minimum. Recent studies reported by the Director of the American Transit Association show that considering the full capacity of a single traffic lane as 100%, a second lane, where channelized traffic is not enforced is actually only 78% efficient; that in the third lane without channelized enforcement the efficiency is only 56% compared with the first lane. Thus is statistically illustrated the waste of street space caused in traffic in our large cities where automotive traffic is weaving in and out between street cars. Of course, it is impossible to furnish accurate figures on the increased safety if all public carrier passengers were enabled to load and unload from a large capacity public carrier operating adjacent to the curb, but such protection would tremendously reduce deaths and injuries in the street.”

Unlike most articulated buses that followed, the joint between the Super-Twin’s front and rear compartments only allowed for the vertical movement of the two attached coaches, no horizontal action was allowed with the turning being accomplished via coordinated action between the two steerable axles – one located at the front, the second at the rear.

Here’s the Italian Stanga-Stanga-BBC, Type Isotta Fraschini TS40 of 1940. It was articulated horizontally and supposedly was steered by the front wheels only.

According to this source, no orders resulted for the lengthy vehicle and it was sold to a Cleveland operator who used it as an electric-powered trolley-bus. Yet this second picture of what is identified as the same vehicle clearly is somewhat different. And both were strictly electric trolley buses.

Although the Twin Coach (and the Isotta Fraschini TS40) articulated trolleybuses were not successful, Twin Coach manufactured fully one-third of all the trolley buses manufactured in North America, manufacturing 670 trolley coaches during its 25 years in business. And of course articulated city buses are now extremely common, and seem to be becoming the default, due to their greater capacity.

But the articulated highway coach never really caught on, as my post on the 1958 Kässbohrer Setra Continental Trailways Super Golden Eagle articulates quite clearly. Now I’m going to have to update those two posts.

 

More on Twin Coach at coachbuilt.com