The Bristol SU ("small, underfloor-engined") chassis featured the same Albion EN250 engine and BMC rear axle as the Albion Nimbus NS3AN with a David Brown overdrive-top five-speed constant-mesh gearbox and a front axle by Kirkstall. The major difference from the Nimbus was that the radiator was mounted at the extreme front of the chassis. EWT 386C (West Yorkshire's SMA17) was later rebuilt with a Perkins H6.354 5.8-litre engine to test its design for use in the Bristol LH, which superseded the SU as Bristol's lightweight chassis.
The single-deck ECW body was just 7.50 feet (2.29 m) wide and used some similar styling elements to those built for the heavier Bristol MW. The bus bodies were 9.42 feet (2.87 m) high but the coaches were a little taller at 9.83 feet (3.00 m); the length varied depending on the chassis and whether it was to bus or coach style (see table below). A forward entrance was provided opposite the driver's position. Seats were forward-facing in pairs, but where wheel arches protruded above the floor of the bus body, the seats were turned sideways to give sufficient leg room.
|SUL||15 feet (4.57 m)||Bus||36||27.83 feet (8.48 m)||1960–1966||118|
|SUS||12.33 feet (3.76 m)||Bus||30||24.16 feet (7.36 m)||1960–1964||25|
|SUL||15 feet (4.57 m)||Coach||33||28.16 feet (8.58 m)||1960–1962||38|
The SUs were concentrated in the south-west of England, with 73% of them being built for the shared fleet of Southern National and Western National (Southern National was formally merged into Western National in 1969). The remainder were sold to six other companies that were owned by the Transport Holding Company.
|Western National||400–403||334 EDV–337 EDV||SUL||coach||4|
|Southern National||404–407||314 EDV–317 EDV||SUL||coach||4|
|Western National||408||922 GUO||SUL||coach||1|
|Southern National||409–411||923 GUO–925 GUO||SUL||coach||3|
|Western National||412–416||917 GUO–921 GUO||SUL||coach||5|
|Western National||417–431||267 KTA–281 KTA||SUL||coach||15|
|Western National||432–435||284 KTA–287 KTA||SUL||coach||4|
|Western National||600–608||672 COD–680 COD||SUS||bus||9|
|Southern National||609–610||681 COD–682 COD||SUS||bus||2|
|Southern National||611–615||667 COD–671 COD||SUS||bus||5|
|Southern National||616–623||318 EDV–325 EDV||SUL||bus||8|
|Western National||624–644||338 EDV–358 EDV||SUL||bus||21|
|Western National||645–653||414 HDV–422 HDV||SUL||bus||9|
|Southern National||654–662||423 HDV–431 HDV||SUL||bus||9|
|Southern National||663–667||BDV 24C–BDV 248C||SUL||bus||5|
|Western National||668–674||BDV 249C–BDV 255C||SUL||bus||8|
|Western National||675–686||EDV 530D–EDV 541D||SUL||bus||12|
|Southern National||687–696||EDV 542D–EDV 559D||SUL||bus||10|
|Bristol Omnibus||300–302||861 RAE–863 RAE||SUS||bus||3|
|Bristol Omnibus||303–306||843 THY–846 THY||SUS||bus||4|
|Bristol Omnibus||307–308||AHW 226B–AHW 227B||SUS||bus||2|
|Southern Vectis||845–852||458 ADL–465 ADL||SUL||bus||8|
|United Automobile||S1–S2||AHN 901B–AHN 902B||SUL||bus||2|
|United Automobile||S3–S5||CHN 3C–CHN 5C||SUL||bus||3|
|United Counties||300–303||HRP 300D–HRP 303D||SUL||bus||4|
|United Counties||304–305||JNV 304D–JNV 305D||SUL||bus||2|
|United Welsh||10–11||752 BWN–753 BWN||SUL||coach||2|
|West Yorkshire||SMA1–SMA6||807 BWR–812 BWR||SUL||bus||6|
|York-West Yorkshire||YSMA7–YSMA12||859 DYG–864 DYG||SUL||bus||6|
|West Yorkshire||SMA13–SMA18||EWT 382C–EWT 387C||SUL||bus||6|
The original operators generally kept their SUs running until the 1970s (Western National's last examples were withdrawn in 1979), afterwards selling many of them to independent operators such as Guernsey Motors. The last one in regular service was 280 KTA (originally Western National 430) which was operated by the Tillingbourne Bus Company until May 2000.
16 Bristol SUs are known to be in preservation: 3 SUS, 6 SUL buses and 7 SUL coaches, although some of the later had their bodies modified in service to make them suitable for operating bus services. The SUL buses include EWT 386C, the Perkins-engined example. 416 HDV was driven from the United Kingdom to India. It then returned to the UK and was then taken to USA and Canada before being sold to a preservationist in Mexico.
|Chassis number||Registration||Model||Body||Original identity||Current identity|
|157.004||672 COD||SUS||bus||Western National 600||Western National 600|
|157.007||675 COD||SUS||bus||Western National 603||Western National 603|
|157.109||336 EDV||SUL||coach||Western National 402||Western National 1202|
|157.025||338 EDV||SUL||bus||Western National 624||Western National 624|
|190.012||416 HDV||SUL||bus||Western National 647||Western National 647|
|190.033||270 KTA||SUL||coach||Western National 420||Western National 420|
|190.036||271 KTA||SUL||coach||Western National 421||Ashtree Coaches 10|
|190.037||286 KTA||SUL||coach||Western National 434||Delta Tours 154|
|190.041||274 KTA||SUL||coach||Western National 424||Western National 1224|
|190.042||275 KTA||SUL||coach||Western National 425||Western National 425|
|190.047||280 KTA||SUL||coach||Western National 430||Western National 1230|
|190.050||862 RAE||SUS||bus||Bristol Omnibus 301||Bristol Omnibus 301|
|190.056||811 BWR||SUL||bus||West Yorkshire SMA5||West Yorkshire SMA5|
|226.012||EWT 386C||SUL||bus||West Yorkshire SMA17||Thornes 71|
|226.022||BDV 252C||SUL||bus||Western National 671||Western National 671|
|234.018||EDV 555D||SUL||bus||Southern National 692||Western National 692|
- "Bristol SU Specification". Bristol Vehicles Website. Retrieved 2012-06-08.
- Billington, Colin (2008). West Country Lightweight Single-Decks. Collaton Raleigh: West Country Historic Omnibus and Transport Trust. pp. 3–29.
- "The History of the Bristol SU". Bristol Vehicles Website. Retrieved 2012-06-08.
- "Bristol SU Survivors". Bristol Vehicles Website. Retrieved 2012-06-08.
- Billington (2008), p.50
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