Objectives

Petrol$-$driven motor vehicles such as the typical domestic car comprise of mechanical and electrical systems that generate heat and energy in close proximity to the fuel, petrol. Since the layout of most cars is somewhat similar and known to many delegates, in this hypothetical exercise, you are required to area classify the vehicle shown in below images.

The task is complete when the sketch of the car has been clearly marked with adequate information on the $$hazard$$ and the area classification assigned to the vehicle in its various conditions of use. Indicate any areas you wish to designate Zone $0,1$ or $2.$ Give justifications for your answers $($Q$1$a$).$

Supplementary instructions

It is appreciated that you may have insufficient information to complete the task. Where you require more information, note this need adjacent to a relevant part or area. The vehicle detail shown is diagrammatic and is specifically for the purposes of this exercise. Any assumptions made should be recorded by appropriate annotations.

Side elevation of car

Plan view of car

Method of approach

$$ Use the principles and terminology outlined in Chapter $3$ of this course.

$$ Assess the risk by taking account of the nature of the hazard.

Consider the likely operational situations:

$$ Parked in a garage.

$$ Parked on the road.

$$ Low speed.

$$ High speed.

$$ Engine running but car stationary

$$ Accidents of varying degree of severity

$$ Fuel leakage and spillage

Your ideas should list the methodology used including:

$$ The identification of all sources of ignition $($electrical and mechanical$).$

$$ The identification of all locations and routes $($storage and piping$)$ of fuel.

Petrol flammability characteristics

$$ Flashpoint: $-40\backslash$deg C

$$ Ignition Temperature: $310\backslash$deg C

$$ Vapour density: $1\mathrm{.}24$

$$ Ignition energy: IIA

$$ Vapour dispersion in still air: $4$ metres in diameter from source of release. $0\mathrm{.}5$ metres high from the level ground

You are urged to consider the following situations:

$$ The vehicle is first started $($from cold$).$

$$ The engine running but the vehicle is stationary.

$$ The car moves slowly, say, below $10$mph$/16$kph$.$

$$ Higher speeds above this value.

$$ Accidents of varying degrees of severity.

$$ Long term storage.

$$ Fuel leaks and spillage.

a$)$ What other influences are present on the behavior of the fuel and$/$or vapour?

b$)$ How do you think the car can be made $$safe$$ from the risk of explosion?