The Seddon Atkinson 400 was the first truly unified range produced after Seddon took over Atkinson in 1970, presented in 1975 with modern steel tilt cabs designed by Ogle together with Motor Panels. It carried the heavier end of the range, with Cummins, Gardner or Rolls-Royce diesels of up to 320 hp and a chassis that was mostly Atkinson.
Seddon Atkinson 400 at a glance
| Maker | Seddon Atkinson Vehicles Ltd, Oldham, England |
|---|---|
| Presented | 1975 |
| Range position | the heavier of the new series: 400, then 200 in 1976 and 300 |
| Cab | steel tilt cab designed by Ogle with Motor Panels |
| Cab mounting | higher than on the 300, with a bigger bumper and integrated headlights |
| Engines | Cummins, Gardner or Rolls-Royce diesels, up to 320 hp |
| Chassis | mostly Atkinson |
| Built at | the Atkinson works, and Seddon’s Oldham plant |
| Body styles | two-, three- and four-axle trucks and a two-axle tractor unit |
| Model numbering | higher numbers meant a higher weight rating |
| Updated as | 201, 301 and 401 in 1981 |
| Known weakness | insufficient rust protection on the cabin |
There is no dedicated Wikipedia article on the 400; this page is based on the Seddon Atkinson articles in English and German Wikipedia, where the series is described in the company history.
History of the Seddon Atkinson 400
Seddon Diesel Vehicles took over Atkinson Lorries in 1970 to form Seddon Atkinson, and the merger initially changed little: Seddon and Atkinson went on building their old ranges in their respective plants. That ended in 1975, when a new unified range appeared with modern steel tilt cabs designed by Ogle and developed together with Motor Panels. The line-up began with the 400 series, followed by the Seddon-based 200 series in 1976 and then the three-axle 300 series, with higher numbers corresponding to a higher weight rating.
The 400 was the heavy one. The Atkinson works manufactured it while Seddon’s Oldham plant built all three lines. Its cab sat higher than the one on the 300, which called for a bigger front bumper with integrated headlights and different wheel wells; the 200 was lower and narrower still. The 400 was offered as two-, three- and four-axle trucks and as a two-axle tractor unit, and under the cab it kept a chassis that was mostly Atkinson.
Power came from a choice of Cummins, Gardner or Rolls-Royce diesels with outputs of up to 320 hp, and Gardner engines were the usual choice in most vehicles of the series. The 400 thus mixed a new, shared cab with familiar proprietary running gear, in the tradition of British value-for-money lorry assembly.
In 1981 the range was updated and became the 201, 301 and 401. The 401 received an improved interior, a changed grille and a much improved gear linkage. A few early 401s were built at Atkinson’s Walton-le-Dale plant before all production moved to Oldham. The Motor Panels cabs had severe rust problems, which forced the introduction of a new anti-corrosion package in the mid-1980s, and both the 400 and 401 series drew heavy complaints over insufficient rust protection. Sales dwindled through the 1980s: in 1985 Seddon Atkinson held about five per cent of the British truck market. The 401 was eventually replaced by the Strato in 1988.
Design and features
- First unified cab: the Ogle and Motor Panels steel tilt cab replaced the separate Seddon and Atkinson designs.
- Heavy-range focus: the 400 was the largest of the new series, above the 200 and 300.
- Engine choice: Cummins, Gardner or Rolls-Royce diesels, with up to 320 hp available.
- Atkinson chassis: the running gear underneath was largely carried over from Atkinson practice.
- Bumper-mounted headlights: a consequence of the higher cab mounting compared with the 300.
Seddon Atkinson 400 versions
- 400 two-axle: the basic rigid lorry.
- 400 three- and four-axle: heavier rigids for higher gross weights.
- 400 tractor unit: a two-axle unit for articulated operation.
- 401 (1981): the updated version with a revised interior, a changed grille and a better gear linkage.
The 400 was replaced at the top of the range by the Strato in 1988, and it shared the Iveco years with the Pacer. More British lorries are in the Seddon Atkinson collection.
Video: Seddon Atkinson 401 Rolls Royce Eagle 325
Video on YouTube.
Sources
- Seddon Atkinson, English Wikipedia: 1975 range, Ogle cab, engines, 401 update, rust problems, market share
- Seddon Atkinson, German Wikipedia: axle configurations, tractor unit, Gardner engines
