Crane Failure, Float Ownership, and a Fixed Hospital Opening
A 12-story, 240,000 sq ft hospital bed tower is 14 weeks into an 80-week schedule. The baseline shows zero float on the concrete frame and 14 days of total float on MEP rough-in. The owner's licensing date is fixed and 10 weeks earlier than baseline completion. Two months in, a tower crane gearbox failure puts the structure 9 days behind. The project manager proposes night crews for the next six floors. The superintendent notes that night pours require a second special inspector, the ready-mix supplier has only two plants and one is committed elsewhere, and the MEP subcontractor's 14 days of float was already consumed by an owner-directed riser relocation. Winter weather typically loses 8 days in January and February. Steel joists have a 10-week lead from a single supplier.
1. Is the 9-day slip necessarily a critical delay, and what analysis should precede approving night crews?
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Not necessarily. The 9 days is a project-level slip, but the controlling question is where it falls relative to the critical path and who owns the float. I would first update the schedule with actual dates and the crane repair duration, then run a separate time-impact analysis for the owner-directed riser relocation. The crane failure and the riser relocation may be concurrent, and only one of them may be compensable.
The structure may still be critical, but the MEP path has now lost its 14 days of float and may also be critical. Night crews on the structure will not recover MEP delays. Before approving them I would confirm: the true remaining critical path; whether the special inspector can cover night pours; whether the ready-mix supplier can actually deliver a second shift; the productivity loss from night work; and the cost per recovered day. A recovery measure that adds cost but recovers no critical-path day is not acceleration, it is waste.
2. Draft a recovery strategy that protects the fixed opening date without exposing the company to a constructive-acceleration claim.
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The strategy should separate entitlement from goodwill:
- Notice and reservation. Notify the owner in writing that the riser relocation consumed float and that the crane failure is a separate event. Request a time extension or a written direction to accelerate.
- Re-sequence before adding shifts. Pre-assemble rebar cages, add a second concrete pump, and move non-critical MEP work to day shift so the tower crane is reserved for structure.
- Targeted second shift. Add night work only to critical structural activities where inspection and concrete supply are confirmed. Do not put the whole project on nights.
- Supply protection. Place a refundable deposit or letter of intent with a second joist supplier, or seek approval for an equivalent substitution.
- Weather and buffer. Use the schedule's weather allowance explicitly, and do not spend it in December.
- Cost tracking. Code all acceleration costs separately and report them weekly. If the owner directed the recovery, submit them; if not, do not waive the claim by performing silently.
3. What records and schedule updates would you require so the company can defend or prosecute a time claim later?
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I would require a weekly updated schedule with actual start and finish dates, remaining durations, and a revised critical path, not just a monthly status report. Daily records should capture crane repair logs, delivery tickets, inspector availability, weather, crew counts, and the reason for any shift in work area. The riser relocation needs its own directive, sketches, and time-impact analysis.
I would also keep a separate acceleration cost ledger: premium time, second-shift supervision, additional inspection, equipment standby, and lost productivity. Photographs should be dated and tied to schedule activities. All notices should be logged with the date sent and the contract clause relied on. The goal is a contemporaneous record that shows which delay drove which activity, because a later forensic schedule built after the fact is always weaker than records made while the work was happening.