Slip form and jump form systems allow continuous construction of tall concrete structures such as cores, towers, and bridge piers. Workers operate on moving platforms at considerable height for extended periods, placing reinforcement and concrete as the form climbs. The systems are complex, the heights are significant, and the work is physically demanding. This talk covers the hazards and controls specific to slip and jump form operations.
Key Hazards
Falls from height from the climbing work platform or through openings in the formwork
Formwork system failure or tilting caused by uneven concrete placement
Workers trapped by the moving platform during climbing or jacking sequences
Concrete burns from prolonged contact during continuous placement operations
Control Measures
Ensure the slip or jump form system is designed by a specialist engineer and inspected before use.
Install full edge protection around all working platforms including inner and outer guardrails.
Brief the team on the climbing sequence, jacking procedure, and emergency stop system each shift.
Place concrete evenly around the form to prevent tilting or eccentric loading during climbing.
Monitor the verticality of the form using survey instruments at the intervals specified by the designer.
Wear alkali-resistant gloves and eye protection throughout all concrete placement operations.
Ensure the emergency stop system is tested and functional before each climbing or jacking cycle.
Provide safe access to and from the working platforms using enclosed stair towers or ladders.
Rotate operatives on the platform to manage fatigue during long continuous pour shifts.
Emergency / Rescue
If the form system stalls or tilts during climbing, activate the emergency stop immediately. Evacuate the platform using the designated escape route. Do not attempt to restart until the specialist engineer has investigated.
Remember
The slip or jump form must be designed by a specialist engineer and inspected before first use
Place concrete evenly around the form to prevent tilting or eccentric loading during climbing
Monitor verticality with survey instruments at the intervals the designer specifies
The emergency stop system must be tested and confirmed functional before every climbing cycle
Rotate operatives to manage fatigue during long continuous pour shifts on the platform
Applicable Legislation: CDM Regulations 2015 · BS 5975:2019 (Temporary Works) · Work at Height Regulations 2005 · Health and Safety at Work etc. Act 1974