A safe system of work, which is capable of recovering casualties and emergency responders, should be put in place. An example of this is a recoverable system using rope equipment, but that may not be appropriate in all circumstances.
Specialist resources may be required to provide or advise on the equipment and safe systems of work appropriate to the type of unstable ground, to support a safe and effective rescue.
Spread the load
Applying pressure to unstable ground will increase the likelihood of collapse. It may also result in a casualty, emergency responder, equipment or appliance sinking or becoming engulfed. The greater the pressure, the higher the likelihood.
If movement on unstable ground cannot be avoided, consider spreading the load, reducing weight and pressure. This can be achieved using specialist equipment or by taking simple actions, such as removing unnecessary equipment, sitting down or leaning back.
Spreading the load may prevent or slow the movement of unstable ground and can be used to stabilise a casualty’s position before rescue.
Equipment to assist with spreading the load includes:
- Mud mats
- Inflatable rescue paths
- Salvage sheets
- Inflatable hose
- Ladders
- Sleds
Stabilise and extricate the casualty
The stabilisation of a casualty should be prioritised before rescue activities commence. This is to prevent further deterioration of the casualty and the incident from the actions of personnel. Stabilisation may include the use of:
- Life jackets
- Throwlines
- Weight distribution devices
- Mud mats
- Reach devices
Mud and other unstable ground creates suction on a trapped person; as they attempt to move a vacuum can be created. Pulling a casualty trapped in mud without having taken prior action to reduce the effects of this vacuum, such as digging out, lubricating or diluting the substance, may cause additional harm.
Excessive mechanical force should not be used to extricate casualties from entrapment in unstable ground due to the required force to release them. Technical rescue teams should be requested at the earliest opportunity, to provide expertise and equipment to release a casualty. As the casualty may be numbed, for example in cold mud, when digging close to them considerable care should be taken.
Before extricating the casualty from unstable ground, check that they are not entangled below the surface. Their limbs should be checked, to ensure they are not in an unexpected position. Failure to do these checks before moving or lifting the casualty could result in further injury to them.
In all but the most minor cases, the casualty should not be allowed to walk out, as sudden release and attempts to stand may induce post-rescue collapse. The casualty should be evacuated in as near a horizontal position as possible and handed over to medical responders for treatment.