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Folke Karlsson
• Mr Folke Karlsson is a big man with a big job—director, engine and transmission design and production, SAAB-Scania cars and commercial vehicles. And like many physically big men who are also engineers he has a gentle, unassuming—almost shy— manner which cloaks an impressive ability.
When I interviewed him at Scania-Vabis' Sodertalje headquarters, Mr Karlsson was able to reveal that the securing of a Swedish military vehicle contract calling for automatic transmission meant that this type of gearbox will become available on Scania trucks. The first prototype is already running. A development of the split-torque type, using a torque converter and planetary gearing, it will be suitable for trucks up to about 35 tons gvw.
Mr Karlsson also revealed that Scania is using wet-paper (Cellulose-fibre) clutch linings on experimental vehicles and is looking at ceramic linings—promising but expensive, he remarked. It is one line of approach to coping reliably with new levels of power and torque. He had just returned from the USA, where Greyhound is working intensively on wet linings which, he thinks. could double clutch life.
SAAB-Scania is well ahead with engine noise suppression and is now launching a big programme on diesel exhaust cleanliness. Folke Karlsson thinks big diesels can be acceptably clean and quiet, and sees no pressing need for truck gas turbines. With the big new diesels he thinks 10-speed gearboxes (where manual) will be ample, and Scania is already finding that on new vehicles with five-speed gearboxes many drivers use nothing lower than third, except for starting.
Mr Karlsson started his career on the shop floor of a small-boat engine works in Southern Sweden where he was born, then moved to a steam turbine company and it was not until he was 23 that he started a formal engineering education, studying for 10 years at high school and Stockholm University (where his 20-year-old son is now showing an interest in engineering). He joined Scania-Vabis as truck designer in 1953 and rose to become Scania's chief transmissions engineer.
Away from the big job, his leisure hours are spent in typically Swedish fashion— sailing and swimming from the family summer house 26 miles south of the Soclertalje factory. B.C.
In view of the brief reference to safety belts in Bird's eye view and Mr Cater's article on cab equipment in last week's CM, you might be interested in the following summary of part of the findings of a new study, in the USA, of trucks involved in accidents where injury resulted.
The investigation was carried out by the Cornell Aeronautical Laboratory's automotive crash injury research programme. In brief, the survey shows that when big artic outfits are involved in severe accidents their drivers are injured more often and more severely than drivers of smaller trucks.
ACIR said the study showed that a smaller percentage of the large artic trailers were travelling at high speed at the time of the accidents than were the smaller pick-up and other single-unit trucks and cars, suggesting that occupants of the larger vehicles might be less severely injured. Not so, ACIR reported, reasoning that the more frequent and more severe injuries suffered by occupants of the artics may be due to several factors: a fairly high rate of ejection from their vehicles, the leading cause of death and injury in accidents; less interior occupant protection for drivers of the large trucks; differences in interior dimensions or differences in accident types.
The study was concerned with 970 occupants of 680 trucks involved in injury producing accidents from 1963 to 1967. The American Trucking Associations and the Interstate Commerce Commission co-operated in the study, which also included accident information supplied to ACIR by North Dakota and Oklahoma.
"The findings suggest that improvements to reduce door openings and associated driver ejection could reduce injury," said John W. Garrett, head of the Cornell Laboratory's accident research branch.
The study reinforces several conclusions that resulted from a pilot ACIR study of truck accidents in 1966.
Accident reports examined in the new study showed that 40.3 per cent of the trucks had at least one door opened during the accident sequence. That rate is nearly four times as great as the rate for late-model cars.
Added to this is the strong relationship between door openings and ejection of the driver or passenger—usually through the open door and far less frequently through a broken window or windscreen.
Of pick-ups and single-unit trucks studied, 60 persons were ejected through open doors, compared with seven ejected through other areas. In artics, the ratio was smaller: 24 ejected through open doors and six through other areas.
"The relatively high percentage of ejections through glass areas in artics may reflect the larger windscreen areas often found in cabs of these vehicles," the ACIR report stated.
At the heart of the report are the findings on the relationship between the degree of driver injury and ejection. In pick-ups, four times as many people were severely injured, or killed, if they were ejected during the accident.
In single-unit trucks, the odds for serious or fatal injury were three to one with ejection, and in artics the odds were nearly five to one.
In addition to prevention of ejection, the ACIR report found a need to reduce the buffeting of occupants within the truck.
The use of seat belts could provide the restraint drivers need, but the report said apparent concern over the chances of fire and load shift may be factors acting against adoption of seat belts in commercial vehicles.
In essence, the driver fears being "trapped" in the truck if it catches fire or if its cargo breaks loose in a crash, ACIR said.
Regarding fire or load shift risks, ACIR found that they are far smaller than the risks involved in ejection.
Some 2.6 per cent of all truck accidents studied-18 of 680 accidents—resulted in fire. Of these, one pick-up, six rigid trucks and 11 artics caught fire.
Drivers received burns in eight of the 18 trucks that caught fire and five drivers—all non-ejectees—were killed. Of 13 cases in which drivers were not ejected, • seven drivers sustained burns, compared with one of four drivers who were ejected.
ACIR said that "in cases of load shift, those drivers remaining in the cab appear to have a lower percentage of fatal injuries than those ejected". The report stated: "The use of seat belts to keep the driver inside the cab would therefore apparently offer some protection irrespective of load shift".
Of four drivers killed in load-shift accidents, three had been ejected from their vehicles. All three were crushed under heavy objects that landed on them after they were thrown out of the vehicle. Four non-fatally injured drivers remained in the vehicle but were injured by forward-shifting loads.
ARTHUR W. PRESTON, London, W1