Oral history of British science
Bridle, Ron (Part 3 of 11). An Oral History of British Science.
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Interviewee's home, Gwent
Bridle, Ron, 1930- (speaker, male)
Lean, Thomas (speaker, male)
Part 3: Remarks on return from Africa: job at Cwmbran; building two houses with his brother in law; duties as as a senior engineer, estate developments, building minor roads and drainage, Llanfrecfa Way; position of senior engineer directing small team, below principle assistant Captain Malcom Evans; colleagues Colonel Borlase and Flight Lieutenant Button, military atmosphere in office; features of starting Cwmbran New Town from scratch, adding services, transfer of material from Cwmbran New Town to Llanfrechfa Way; use of a pug mill to mix material. [06:36] Remarks on Cwmbran New Town development: short description of scheme; china tablets to hold drawings; laying out roads in straights and curves; equipment of a civil engineer; sloping of roads around curves to counterbalance centrifugal force, need for chipped roads to keep friction up; use of pre-cast beams to build bridge over railway; materials used for building bridges, block work, stone blocks, brick work, reinforced concrete, pre-stressed concrete, post stressed concrete. [12:15] Remarks on Cwmbran bridges and process of designing a bridge from scratch: material choices, decided by economy and interest; decisions of type of bridge to build, later cause célèbre of Tinsley Viaduct price; [pause 15:10] RB graduates winning Miller Prize for Llanfrechfa Way bridge work; starting with bridge abutments, mass wall and reinforced concrete cantilevered wall; adding deck, Llanfrechfa bridge use of post-tensioned beams; difference between pre and post-tensioning of concrete, concrete's inability to carry tension, comparisons with use of steel I beams and box girders. [20:30] Remarks on problems with box girder bridges later in RB's career: Merrison committee; human error mistakes involved in bridge collapses in bridges in Pembroke, Koblenz and Yarra; safety concerns, anecdote about RB woken by news of collapse of Loddon bridge, checking of calculations. [25:50] Remarks on: surveying work and setting out before building a bridge; anecdote about bridge designer Cyril Lawrence and pre-cast beams; Merrison safety checks and certificates, adapted by RB later in career for all bridges; taking boreholes of ground around bridge; drawing bridge and surrounding features; problem of drainage in Cwmbran; many calculations involved in designing a bridge, improved calculator technology; description of calculations involved in planning road, area calculations from perlmeters and perimeter; [30:09] stress calculations for bridge, balancing the stresses on a bridge, risks of concrete cancer, such as Monmouthshire council offices. [32:40] Remarks on road building concerns, in the example of a motorway: consultation process; public enquires, anecdote about re-routing around an old people's home; anecdote about someone trying to break into RB's office to look at plans; need for care over optical illusions on a road. [37:00]
Interview with civil engineer Ron Bridle