Minitram was anautomated guideway transit system studied by the Transport and Road Research Laboratory (TRRL), part of the UKDepartment of the Environment'sMinistry of Transport. The system was based on small, completely automatedtram-like vehicles of about 25 passengers that could be connected together into three-car trains to increase capacity. Proposed designs were submitted byHawker Siddeley Dynamics (HSD) andEASAMS (part ofGEC). HSD's system used rubber wheels and EASAMS' steerable steel ones, but the projects were otherwise similar and notably shared alinear motor for propulsion and mostbraking. A series of failed sales efforts in the UK and to theGO-Urban system inToronto, combined with decreased government spending in the 1970s, led to the concept being abandoned.
During the 1960s a number of influential studies were published on the nature and future ofmass transit systems. Primary among these were a series of reports from the US known collectively as theHUD reports. The HUD reports concluded that existing forms of transit could not compete with the convenience of car driving. If such systems were to be successful, they would need to offer tighter schedules to reduce waiting, smaller cars with fewer passengers, and more direct routing to eliminate intermediate stops. The result was thepersonal rapid transit concept, or PRT.[1]
The reports suggested the only way to offer all of these features would be to use extensiveautomation. Systems were imagined with driverless vehicles with sizes anywhere from three to 20 passengers, normally travelling at fixed speeds to reduce timing complexity, with stations built "offline" on sidings to allow traffic to bypass intermediate stops. Even with relatively slow cruise speeds, end-to-end trip times would be better than existing mass transit systems, and especially cars.[2]
The publication of the HUD reports, along with considerable development funding by theUS Congress, led to major development efforts in most of the industrialized countries around the world. Four major developments were underway in the US, two in France, two in Germany, and two in Japan. The UK initially entered the fray with early studies on theCabtrack system, but a political firestorm followed the publication of proposed station designs and the concept was abandoned.[3]
Out of the ashes of the Cabtrack debacle came Minitram, designed to be technically simpler than Cabtrack, using on-line stations and scheduling and routing much more similar to conventional metro systems. The concept was no longer along the lines of the PRT systems, and was essentially a smallmetro system, with small 20 to 25-passenger cars that could automatically link together to reduceheadway and thereby increase route capacity. This "automatic platooning" concept also allowed multiple routes in low-volume areas on the outskirts of the network to all feed into a small number of high-volume routes in the downtown cores. This was a topic of some research at the time, notably the FrenchAramis project.[4]
Initial studies by the TRRL demonstrated route capacities greater than Cabtrack, less construction for the same capacity, and better fare box returns.[5] The studies examined vehicles with 14 to 20 passengers running on elevated tracks with 30 second minimum headways, maximum speeds of 55 km/h and average speeds including stops of 40 km/h.[6] Several potential development sites were considered, includingLondon'sDocklands area[6] and betweenCroydon andNew Addington.[7]
The most serious study was for a line inSheffield which connected the city's spread-out shopping areas. A complete report on the route was published in 1974 by Robert Matthew Johnson-Marshall, calling for a total of 2.5 km of double-track forming roughly a U shape with nine stations. Peak capacity with three-car trains was 5,400 passengers per hour, reducing to as little as 180 per hour when running single cars at off-peak times with 5 minute headways.[8] The government also provided some money toBritish Rail to study amaglev solution along the same routes.[9]
On 22 May 1975 the Minister for Transport cancelled the system. He argued that the system was not ready for deployment, and the cancellation was final. His argument for final cancellation was to allow the city to consider other transportation options.[10] This eventually took the form of the existingSheffield Supertram system, whose downtown route from City Hall to Park Grange follows the original Minitram route.[11]
The only other interest expressed in the Minitram system was by theGO-Urban development forToronto.Hawker Siddeley Canada was already a major provider of equipment forOntario, including both theH-series cars for theToronto Transit Commission'ssubway system and the newly developedBiLevel Coach forGO Transit's regional rail networks.[12] After the initial downselect from 18 different proposals, the project selected theFord ACT, Hawker's version of Minitram, and theKrauss-Maffei Transurban. Ford withdrew their system from the contest, leaving the two platooning systems (Transurban could operate in three-car trains) in the running. Given the high-tech goals of the project, it was considered a foregone conclusion that the Transurban would win the contest, as announced on 1 May 1973.[13]