Chapter 21 — Key Takeaways

A one-page reference card. If you are sitting in a preconstruction meeting eight months early, arguing about a tower crane with a superintendent who has thirty-one years in the field, this is the page.

Key Takeaways

• Equipment selection is a schedule decision priced in dollars. It is not a rental decision. The person who wins that argument is the one asking what the work requires — in what sequence, at what radius, against what constraint — not the one comparing hourly rates.
• Five questions, in this order. (1) What production rate do I need? (2) What physical constraints apply — reach, capacity, access, ground bearing, height, obstructions, airspace? (3) What does it cost per unit of production? (4) What happens when it breaks? (5) Who owns each risk in the arrangement? Managers who start at question 3 reliably buy the wrong machine.
• Compare system cost per unit produced, never machine cost per hour. On Northgate's export, the small excavator won on machine cost ($0.585/LCY against $0.685) and lost on system cost ($5.75/LCY against $5.29), because the excavator is 13 percent of the hourly fleet and the trucks are 80 percent. Speeding up the loading tool shortens everybody's day.
• Own-versus-rent is a question about your organization, not about the machine. Break-even on Kestrel's excavator is 1,372 hours a year; actual utilization is 1,250; the gap is $1,594 a year, which makes it a coin flip decided correctly on things that are not money — availability at 5 a.m., operators who know its quirks, no argument about the dent.
• The sensitivities matter more than the base case. A 15 percent fleet rental discount moves break-even to 4,235 hours a year and eliminates the ownership case entirely. Cutting the repair reserve from 65 percent of depreciation to 45 percent moves it to 1,033 hours and makes ownership easy. The ownership case is won or lost in the shop, not in the purchase negotiation.
• Rental tiers break at about three. Three days of daily rental costs more than the week; three weeks of weekly costs more than the month. Eleven days rented daily instead of monthly threw away $3,750 on one machine on one scope — and that habit runs $25,000 to $40,000 across a job without ever appearing as a variance anybody can name.
• An internal equipment rate that is not honest makes your cost report fiction, in both directions. Too high and your PMs rent outside, utilization collapses, and the spiral is real. Too low and the equipment division loses six figures nobody can find. On a GMP or cost-plus job, disclose the rate during negotiation — that is how you avoid a six-figure audit finding in month nineteen.
• One truck too many costs truck rent. One truck too few costs calendar. On the canonical 40,000 LCY export: 14 trucks costs $13,101; 12 trucks costs $26,864 once you price two calendar days on the critical path at $10,650. And at 92 percent real availability a nominal fleet of 13 puts 11.96 trucks on the ground — the "extra" truck is the spare you already needed and did not price.
• Capacity is indexed on radius, not boom length, and chart values are gross. Net capacity = chart gross − load block and hook − slings and shackles − spreader bar − jib and rope deductions. Never interpolate in your favor: round to the longer radius row and the longer boom column.
• The rooftop air handler failed at 111 percent of chart. 15,700 lb suspended against 14,100 lb gross, or 14,200 lb of load against 12,600 lb of net. That is not a critical lift requiring extra planning. It is a prohibited lift, and there is no paperwork that makes 111 percent acceptable.
• Radius is almost always the cheapest variable you control. Moving the setup fourteen feet closer bought 5,100 pounds of capacity for $4,900 — against $11,100 to split the unit (plus three weeks of lead time) and $19,600 to bring a bigger crane. Lighter rigging is real and it is rarely the fix.
• Ground kills more picks than charts do. Outrigger loads are not one-quarter each: the worst float on that pick carried 62 percent of 191,700 lb, or 118,900 lb on a 4 SF float — 29,725 psf against 4,000 psf allowable, seven times what the soil would take. And a mat only spreads load if it is stiff enough to spread it. Ask what is under the mat: trenches, vaults, tanks, podium decks.
• Crane time is the scarcest resource on the site. A tower crane at $77,602 a month is $398 per available hour and $621 per productive pick-hour — closer to $989 with a raising gang standing under it. Twenty minutes of morning indecision is $4,347 a month and $47,800 over an eleven-month term.
• For a tower crane, the number you negotiate with the neighbor is the out-of-service radius, not the working radius. A freestanding hammerhead must weathervane out of service, so its jib crosses the neighbor's airspace twenty-four hours a day for the whole term. That is what a luffing jib is for, and it is routinely worth the premium on a constrained site.
• Struck-by and caught-in/caught-between are two of OSHA's Focus Four, and earthmoving concentrates both in one place. What prevents it is a system: an internal traffic control plan that designs out backing, high-visibility apparel, a spotter with exactly one job, positive communication before movement, swing-radius barricading on every rotating machine, and seat belts in every machine with rollover protection.
• The operator and the lift director have unqualified authority to refuse a lift. No superintendent, project manager, or owner's representative overrides that — not for schedule, not for a delivery truck that has to leave. Odessa Pruitt's refusal on a windy Friday cost about $3,100 and was the cheapest money spent that month. Schedule pressure is a hazard, and it is the only hazard that gets worse when you are behind.
• Concrete is the one operation you cannot pause. Size the plant, not just the pump: trucks per hour = placement rate ÷ truck capacity; trucks in rotation = trucks per hour × cycle hours. A $1,900 backup pump stands against a $43,125–$69,125 stopped-pour exposure and an unplanned cold joint.
• The machine is never the cost — the crew waiting on it is. Six hours of downtime on the excavation spread was $22,460, of which the machine itself was $239. Two percent. "We got a cheap rental" is one of the most expensive sentences in construction.
• Mobilization and demobilization is the money everybody forgets. The crawler crane's mob and demob on Northgate was $38,000 — 6.6 percent of the entire crane cost, and none of it appears on any rate sheet.

Action Items — What to Do on Your Job This Week

1. Pull six months of fuel invoices and divide by telematics hours. Replace the dealer's spec-sheet burn figure with your own. Two hours of work that improves every equipment decision you make for a year — and it is the signal that would have caught a 38 percent fuel overrun before it reached $41,000.
2. Build the one-page rental log — machine, vendor, rate tier, on-rent date, off-rent date, and the name of the person who owns the return. Then find every machine sitting on a daily rate past day three and convert it.
3. Take the heaviest pick on your next four weeks of schedule and work it to net capacity. Load, rigging, block, spreader, radius, boom, percent of chart. If you cannot produce that number in ten minutes with the chart in front of you, that is the skill to fix this week.
4. Ask your superintendent what tomorrow's pick schedule is. If the answer is "we'll sort it out in the morning," you have just located $621 an hour of leakage.
5. Open your cost report and see whether idle and standby have their own code. If they are buried inside the working code, you cannot explain any equipment variance and you cannot support a time-impact analysis.
6. Add a mobilization and a demobilization line for every machine on your equipment schedule and sum the column. Most people find five to eight percent of their equipment cost that was never estimated.
7. Walk the site and look at the swing radius of every machine with a rotating superstructure. Barricaded or not. That is a fifteen-minute walk against a crush injury.

Common Mistakes — and the Fix

Decision Framework

The tower-versus-mobile decision, in the order it should be asked

Do not start with price. Start with the work, and let the machine fall out of it.

  1. WHAT MUST BE PICKED?      Heaviest piece, its location, and the radius
                               from every legal setup point. Model it if you can.
                               If half your column lines light up red, you have
                               your answer and it is not a pricing question.
              │
              ▼
  2. WHAT IS THE DURATION?     Weeks of hook demand across ALL trades — steel,
                               deck, precast, curtain wall, roof units, MEP.
                               Short and discrete favors mobile. Long and shared
                               favors tower.
              │
              ▼
  3. WHAT GROUND DO YOU HAVE?  Setup pads, mat road, allowable bearing, what is
                               buried, and how much parking you are willing to
                               take from an owner who has to run a clinic.
              │
              ▼
  4. WHOSE AIRSPACE?           Working radius AND out-of-service radius. A
                               hammerhead weathervanes. Get the license in
                               preconstruction — ours took 8 weeks and $22,000.
              │
              ▼
  5. NOW PRICE IT — ALL OF IT. Tower: rental + foundation + erect/dismantle +
                               tie-ins + jumps + operator + oiler + inspections
                               + power + insurance, amortized over the term.
                               Mobile: rate + mob + demob + assist crane +
                               mats + setup days + the pick count.
              │
              ▼
  6. CONVERT THE SCHEDULE      Days saved are only money if a successor actually
     TO DOLLARS — HONESTLY.    starts earlier or you bank named float.
                               $5,150/CD extended GC; $10,650/CD with LDs.

The tie-breaker, when the money is close: the tower buys availability for every trade for the whole term; the mobile buys flexibility and gives the ground back. On a tight urban site next to something that stays open, the constraint is usually airspace and ground, not dollars — and the third option, a crawler working inside the footprint on a mat road, is the one nobody in the room proposes and the one that won on Northgate.

Before you agree that a pick is fine

Ask these four and accept no vague answers:

1. Percent of which chart? Boom length, radius, counterweight, outrigger extension, quadrant.
2. Did that percentage include every deduction? Block, hook, rope, stowed jib, sheave, slings, shackles, spreader, tag lines. Eight hundred pounds missed on a 15,000-pound pick moves you five points.
3. Is it critical for a reason other than percentage? Multi-crane, personnel platform, blind pick, over an occupied structure, near power lines, questionable ground, high sail area in wind.
4. Who verified the load weight, and from what document? A shipping ticket, a certified weight, or a calculation with the math attached. Never "it looks like about."

Own, rent, lease — the quick screen

The numbers to keep in your head

The one test

Can you state, in one sentence, what schedule outcome this machine is buying and what it costs per day of that outcome? If the answer is a rental rate, you are pricing machines. If the answer is "it holds the enclosure sequence to eleven months at $621 a productive hour," you are managing a project.