“reasonably practicable” (1)• reasonably practicable, as defined by Judge Asquith in Edwards vNational Coal Board (1949):• Reasonably practicable is a narrower term than physically possible, and seemsto me to imply that computation must be made by the owner in which thequantum of risk is placed on one scale and the sacrifice involved in themeasures necessary for averting the risk (whether in time, money or trouble)is placed in the other, and that, if it be shown that there is a grossdisproportion between them – the risk being insignificant in relation to thesacrifice - the defendants discharge the onus on them.• In other words, if the overall cost of the measures required tominimise the risk of injury grossly outweigh the benefit arising fromthe reduced risk, then no action is necessary
Hazardthe potential to causeharm, be that injury topersons or damage topropertyHSE. 2000: Successful health and safety management, HSG 65
Riskthe likelihood that anundesired event will occurdue to the realisation of ahazardHSE. 2000: Successful health and safety management, HSG 65
Targeta person or object, whethermobile or fixed, within thepotential zone of impact of atree or its branches, whichmight be harmed as a result ofthe partial or total failure of thetreeNOTE: The term can also referto a pedestrian or vehicularroute where harm might thusoccur.BSI. 2010: BS 3998: 2010 Tree work – Recommendations
Is this ahazard tree?“Unless a target is present a tree cannot be hazardous.”Undeniably it has a number ofstructural defects that afford the treethe potential to cause harm, but arethere any targets?
Is this ahazard tree?There is a track next to thetree, the level of use willdetermine the level of risk totargets and so whether, or not,something might be done:“Can a problem be foreseen? If so• What is its likelihood of occurring• What is the likely consequence of itsoccurrence?• Is it reasonable to protect against it?”