Free calculator · cranes & logistics
Is the crane actually the bottleneck?
Every trade on a tower blames the crane, and sometimes they are right. This works out what the crane can actually deliver in a day against what the job is asking of it — and where the line is between a busy crane and one with no capacity left to absorb a single thing going wrong.
Questions
What utilisation should I be aiming for?
Somewhere between about 60 and 85 per cent for a job that still works when something goes wrong. Below that you are paying for a crane that sits. Above it there is no slack: one breakdown, one windy morning or one late truck and the backlog does not clear that day, or that week.
Why does the tool care about the 85 per cent line?
Because queueing gets non-linear near capacity. As demand approaches what the crane can deliver, waiting time climbs steeply rather than gently, so the last few per cent of utilisation cost far more in trade downtime than they save in crane hire.
What should I put in for time lost?
Everything that is not lifting: crib, refuelling, servicing, wind stoppages, shift change, and waiting on a dogman or a landing area to clear. Twenty per cent is a common starting point on a busy tower, and honest sites usually find it is higher.
It says I have capacity but the trades still cannot get a lift.
Then the constraint is how lifts are allocated, not how many are possible. Average utilisation hides morning peaks. A booking system that spreads demand across the day will usually beat hiring a second crane, and it is a great deal cheaper.
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Related free tools
One crane, one day. A tower runs this for two years.
The paid system books the crane against the work fronts that need it, so the morning pile-up shows up as a scheduling conflict the day before rather than an argument at 6am.
