One Wrong Message Can Move a Crane the Wrong Way

A competent Slinger/Signaller does much more than simply attach lifting accessories to a load.

During a lifting operation, the slinger may be responsible for selecting and attaching the correct lifting accessories, checking the load is secure, controlling the load, maintaining the exclusion zone and directing the crane operator using recognised signals or radio communication.

When the operator cannot see the load or landing area, clear communication becomes even more important.

Consider a tower crane carrying a heavy load to a blind landing position. The operator is relying entirely on the slinger’s radio instructions.

Instead of clear commands, the radio becomes filled with conversation:

“Yeah mate, keep coming… little bit… little bit… no, the other way… watch it… hold on… STOP!”

By the time STOP is given, the crane may already have moved in the wrong direction.

The load could strike the structure, trap an installer, enter another crane’s envelope or swing towards personnel.

Radio communication during a lift is safety-critical communication, not casual conversation.

What Went Wrong

Unclear terminology was used.

Instructions were too long.

Unnecessary conversation occupied the radio channel.

Direction was not clearly identified.

The operator had to interpret what the slinger meant.

No positive confirmation was used.

Critical information became mixed with irrelevant conversation.

Key Lessons Learned

A Slinger/Signaller needs competence in four connected areas:

•Sling the load correctly.

•Check the load, lifting points, accessories, WLL, configuration and security before lifting.

•Direct the crane correctly/Communicate correctly.

•Position yourself where the load can be safely managed.

Instructions should be short, clear and understood by the operator.

If communication becomes unclear:

STOP THE CRANE.

Never guess what somebody meant.

Example of Good Radio Communication

A simple exchange could be:

Slinger: “TC1, this is Slinger 1. Radio check.”

Operator: “TC1 receiving you loud and clear.”

Slinger: “TC1, hoist slowly.”

Operator: “Hoisting slowly.”

Slinger: “Slew right slowly.”

Operator: “Slewing right slowly.”

Slinger: “Ease down.”

Slinger: “Two metres to landing.”

Slinger: “One metre.”

Slinger: “500 millimetres.”

Slinger: “STOP.”

The exact terminology and protocol should follow the site’s agreed system and applicable recognised signals.

Example of Dangerous Communication

“Come towards me.”

Towards who? From the operator’s perspective or the slinger’s?

“Go over there a little bit.”

Where is there?

“Keep going… keep going… keep going… WHOA!”

How far? In which direction?

“Yeah, you’re alright.”

That isn’t a crane movement instruction.

Ambiguous language forces the operator to interpret rather than execute a defined instruction.

Radio Discipline

During safety-critical crane movements, keep the channel clear.

Avoid jokes and unrelated conversations.

Use agreed crane identification where several cranes share the site.

Give one instruction at a time.

Use clear directions agreed during the briefing.

Repeat or acknowledge critical instructions where required by the communication procedure.

STOP must always mean STOP.

If radio communication is lost during a blind lift, the operator should follow the agreed lost-communication procedure, normally bringing movement to a safe stop rather than guessing what happens next.

Safety Recommendations

Brief the communication method before lifting starts.

Confirm who is authorised to signal the operator.

Test radios before the first lift and after breaks where appropriate.

Use recognised hand signals when applicable.

Use dedicated radio channels/call signs on multi-crane sites where required.

Keep radio instructions short.

Avoid ambiguous terms such as “over there”, “my way”, “your way” unless those terms have been specifically defined in the site’s communication system.

Stop immediately when communication becomes unclear.

Incident Source

Safety-learning scenario based on common communication failures during crane operations.

Poor radio discipline can turn an otherwise correctly planned lift into an uncontrolled movement, particularly during blind lifting where the operator depends heavily on information from the Slinger/Signaller.

Regulatory Mapping

● LOLER Reg. 8 – Lifting operations must be properly planned, appropriately supervised and carried out safely.

● PUWER Reg. 9 – Personnel must receive adequate training and instruction.

● BS 7121 series – Lifting operations require suitable signalling and effective communication between members of the lifting team.

● Health and Safety (Safety Signs and Signals) Regulations 1996 – Provides requirements relating to verbal communication and hand signals used to direct hazardous manoeuvres.

Key Point

The crane operator moves the controls.

The slinger moves the crane through communication.

So don’t fill a safety-critical radio channel with:

“Mate… maybe… little bit… over there… keep going…”

Give one clear instruction.

Receive confirmation.

Watch the movement.

And if communication becomes unclear:

STOP.

Wolf Lifting Dynamics | www.wolflifting.uk | Case Study 131

0 comments