A Deflectograph is a survey vehicle used to produce data for the assessment of pavement strength. It is a lorry based system, with a pair of wheels at the front and a pair of double wheels at the rear. At the start of testing a pair of deflection beams are lowered onto the road surface. The Deflectograph then moves forward, so that the double wheels on the rear of the vehicle straddle the two beams. This causes the pavement to deflect (due to the vehicle’s weight) which is measured in the two beams. Once the rear wheels have reached the end of the beams, the beams are brought forward and the process is repeated again. This results in deflection measurements taken at approximately 4m intervals. These machines survey at 2.5km/h and are further discussed in HD29 (DMRB Volume 7 Section 3).
The Accreditation and QA requirements for these devices are given in the Accreditation and QA specification .
If you are looking for a contractor to carry out Deflectograph surveys compliant with HD29 on your behalf, you may wish to check the list of Deflectograph Survey devices below. On this page you can also find the latest accreditation certificates. Certificates from previous years can be found here.
|Certificate||Reg plate||Operating Company|
|2017_DFG_M05_D962 JRU||D962 JRU||WDM Ltd|
|2017_DFG_M08_BYW_80V||BYW 80V||WDM Ltd|
|2017_DFG_M09_VGV_182X||VGV 182X||WDM Ltd|
|2017_DFG_M10_F569_JBB||F569 JBB||WDM Ltd|
|2017_DFG_M12_EOU_230W||EOU 230W||WDM Ltd|
|2017_DFG_M14_B195_CFW||B195 CFW||Lincolnshire County Council|
|2017_DFG_M15_ACZ_3268||ACZ 3268||DoE Northern Ireland|
|2017_DFG_M16_B880_XOU||B880 XOU||WDM Ltd|