Okay, let's break down this task and see if the estimated time seems reasonable.

Understanding the Task Equipment

Heavy box (800 lbs with covers, 400 lbs without). It's being lifted by a crane onto a roof 90 feet high.

Movement

The box then needs to be moved 50 feet on the roof to its final location.

Drilling

32 knockouts (KOs) with a 4-inch diameter need to be drilled in the box.

Team

Three men.

Estimated Time

2 to 2.5 days.

Analyzing the Time Estimate

Let's consider each part of the job:1. Crane Lift and Placement



Crane Coordination

This involves coordinating with the crane operator, ensuring proper rigging, and safety checks.

Placement

Carefully positioning the box on the roof. Wind conditions and obstacles on the roof could slow things down.

Time Estimate

A few hours seems reasonable for this part.2.

Moving the Box on the Roof



Methods

How are they moving it? They might use rollers, dollies, or a come-along winch.

Floor Condition

The surface of the roof will greatly impact this. Is it smooth and even, or uneven and covered with gravel?

Obstacles

Are there other HVAC units, pipes, or roof penetrations to maneuver around?

Safety

The crew will need to take extra steps to protect the roof and protect themselves from falling over the edge.

Time Estimate

This could easily take a half day or more depending on how difficult the move is.3.

Drilling the Knockouts



Tooling

What kind of drill are they using? A hole saw or a punch set? Hole saws are much slower.

Material

What's the box made of? Thick steel or thin aluminum?

Accessibility

Are the locations of the KOs easy to reach?

Time Estimate

Let's assume each knockout takes 15 minutes (including setup, drilling, and cleanup). That's 15 minutes/KO 32 KOs = 480 minutes = 8 hours of drilling.4.

Other Factors



Safety Meetings & Planning

Time for safety briefings, job hazard analysis (JHA), and planning the move.

Breaks

Required breaks for the crew.

Unexpected Delays

Weather, equipment malfunctions, unexpected obstacles.

Coordination with other trades

May have to coordinate with other trades on the roof.

Assessment Drilling Time

The drilling alone accounts for almost a full day of work.

Movement Time

Moving the box on the roof is the biggest unknown. If it's a difficult move, it could easily take another half day or full day.

Overall

2 to 2.5 days for three men seems plausible, but perhaps on the high side. It's reasonable if the roof movement is difficult or the drilling process is slow, or a coordination with other trades on the roof, like the electrician for power to the drill.

Questions to Ask / Things to Consider How will the box be moved on the roof? Get details on the planned method and equipment. What is the roof surface like? Is it smooth or rough? Is it level? What is the box made of? How thick is the metal? What tooling will be used to drill the knockouts? This is a huge factor in drilling time. A hydraulic punch set is much faster than a hole saw. Are there other trades that will need to be there while this is taking place?* Are there any constraints on the roof that might take more time?In Conclusion

Without more information about the specific challenges of moving the box on the roof and the drilling process, it's hard to say definitively if the estimate is too high. But is doesn't seem unrealistic. If you can get answers to the questions above, you can get a better feel for whether the time estimate is truly justified. Flag for review