CSCS Tower Crane cheat sheet

Hammerhead (horizontal jib) cranes: jib and counter-jib are fixed horizontal; trolley travels along the jib to change radius.

Luffing-jib cranes raise/lower the jib to change radius; used where horizontal jib cannot swing clear of adjacent structures.

Self-erecting cranes fold and unfold hydraulically; typically limited height and capacity, erected without a separate mobile crane.

Base types: fixed foundation (concrete pad or ballast block), rail-mounted (traveling), and climbing (internal or external to a building core).

Slewing assembly sits between the mast top and turntable; it allows 360-degree rotation of jib and counter-jib as one unit.

Counter-jib carries counterweights and often the hoist machinery; counterweight mass balances the overturning moment from jib loads.

Trolley (distribution) carriage moves along the jib; hoist rope passes from trolley sheave to hook block.

Mast sections are bolted or pinned lattice modules; climbing cranes add sections at a climbing frame as the building rises.

Foundation must be designed for crane reactions: vertical load, overturning moment, and horizontal shear; concrete strength verified before erection.

Erection sequence typically: base/foundation check, mast assembly, slewing unit, cab and turntable, counter-jib with counterweights, jib, then reeving.

Counterweights are installed before the jib is assembled to keep the crane balanced during erection.

Climbing: crane is supported by a climbing frame anchored to the structure; guide rollers and wedges are reset after each climb.

Free-standing height limit is defined by the manufacturer; beyond it, the crane must be tied to the structure at specified intervals.

Dismantling reverses erection: remove jib, then counterweights, then counter-jib, then mast sections, using a mobile crane or self-lowering system.

Exclusion zones and a documented lift plan are required for erection, climbing, and dismantling operations.

Wind speed limits for erection/climbing are manufacturer-specified and are typically lower than normal operating limits.

Rated capacity = the lesser of the load-chart value at that radius and any reduced capacity from configuration (jib length, counterweight, reeving).

Load moment = load x radius; the chart is fundamentally a limit on overturning moment plus structural limits.

Working radius is measured horizontally from the slewing centre to the hook/load centre of gravity, not along the jib.

Deduct from rated capacity: hook block, slings, spreader beams, and all rigging below the hook.

Two-part (or more) reeving increases capacity for heavy lifts but reduces maximum hook height and hoist speed.

Sling angle: tension in each leg = load / (number of legs x sin of angle to horizontal); shallow angles greatly increase leg tension.

Shock loading from rapid slewing, hoisting, or sudden stops can exceed static chart values and must be avoided.

A lift is critical when it exceeds a defined percentage of rated capacity (commonly 75%) or involves multiple cranes or personnel.

Daily checks before first use: wire rope for broken wires, kinks, corrosion, and correct spooling on the drum.

Check hook for cracks, deformation, throat opening, and that the safety latch closes and seats correctly.

Inspect limit switches (hoist high, hoist low, trolley, slewing) and the moment/overload limiter for correct function.

Verify anemometer reads correctly; wind speed indication is a primary safety instrument.

Check brakes (hoist, slewing, trolley) for holding ability and adjustment; check for oil or grease on brake surfaces.

Inspect structure for loose or missing bolts, cracked welds, corrosion, and deformation of mast or jib members.

Check cab controls, emergency stop, and all alarms/indicators; confirm two-way radio communication works.

Record results in the inspection log; defects affecting safety must be reported and the crane taken out of service until rectified.

Only one designated signaler directs the crane at a time; the operator obeys that person unless a stop signal is given by anyone.

Standard hand signals: raised fist = stop; arm extended upward with index finger = hoist; arm extended downward = lower.

Emergency stop signal is valid from any person and must be obeyed immediately.

Operator must not move a load over personnel; use tag lines to control rotation and swing.

Before slewing, confirm the path is clear and warn personnel; allow for load swing and pendulum effect.

Never leave controls with a load suspended; lower the load, set the brake, and shut down per procedure.

Permit-to-work and lift plans apply to critical or complex lifts; the operator confirms load weight and rigging before hoisting.

Loss of communication during a blind lift: operator stops and holds until communication is restored.

Stop operations when wind speed reaches the manufacturer's limit; in-service and out-of-service limits differ.

Out-of-service: slew to the manufacturer's specified free-slew or park position and release the slewing brake as instructed.

Wind load on the load and jib increases with the square of wind speed; large flat loads act as sails.

Minimum approach distance to overhead power lines must be maintained per local rules; treat lines as live until confirmed de-energized.

Use a spotter/banksman when working near power lines; never allow jib, rope, or load within the exclusion distance.

Check for obstructions: adjacent buildings, other cranes, and aerial hazards; use anti-collision or zoning systems where fitted.

Ground conditions matter: crane base or rail track must be stable; check for settlement, undermining, or excavation nearby.

Lightning and electrical storms: cease operations and follow the site's storm procedure.

Follow the manufacturer's maintenance schedule for intervals and lubricant types; record all work in the maintenance log.

Wire rope: lubricate per manufacturer; inspect for broken wires and wear; replace when criteria (e.g., broken-wire count) are met.

Brake adjustment: maintain correct air gap/clearance; brakes must hold rated load without slipping.

Slewing ring and pinion require periodic greasing; check for wear, backlash, and loose bolts.

Limit switches and overload limiter must be tested and recalibrated after adjustment or repair.

Bolted connections: check torque on mast and jib bolts at specified intervals and after climbing.

Hydraulic systems (luffing/self-erecting): check fluid level, leaks, and hose condition; never adjust relief valves without authorization.

Minor adjustments only within the operator's competence; structural or safety-critical repairs require qualified personnel.

Operators must hold the required licence/competency for the crane type and be medically fit.

The operator is responsible for the daily pre-use inspection and for refusing unsafe lifts.

Lift plans, risk assessments, and method statements are required for erection, climbing, dismantling, and critical lifts.

Thorough examination (statutory inspection) is required at defined intervals by a competent person; records must be kept.

Manufacturer's manual and load chart are the governing documents for operation and configuration.

Report all defects and incidents; do not operate a crane with a known safety defect.

Keep the logbook and inspection records up to date; they are legal records.

Follow site rules for permits, exclusion zones, and communication; cooperate with the appointed banksman/signaler.