Chapter 18 — Quiz

B. A and D are outcomes that sometimes follow; C is factually wrong and legally hazardous, since roughly 85% of Northgate's craft hours belong to subcontractors whose means and methods you do not direct. The product is a condition: work that is available — area ready, material present, information exists, access open, preceding trade finished, inspection passed.

C — waiting. Crews wait because somebody upstream did not finish something: material, information, access, a lift, an inspection, another trade. That "somebody" is frequently the GC. Note that D is not waste at all — a toolbox talk is production of safety, not a loss.

B. You cannot leave a reference point where the building is going. Set it a stated distance outside, and write the offset on the stake, the hub, and the layout sheet — building to an offset line believing it is the grid line is one of the most expensive layout errors there is.

C. 412,000 ÷ 48 = 8,585 sheets. 8,585 ÷ 48 = 178.9 crew-hours × 2 workers = 358 MH. 358 × $52.00 = $18,616. And if the second move crosses floors it also consumes roughly 3.6 full days of hoist capacity that belonged to everyone else.

B. Everything must go up and most of it must come back down as waste, and there are usually one or two ways up. All the others are real constraints, but the hoist and the crane are the ones that stop the whole building at once.

B. Ninety minutes of the day's 8.5 available hours — about 18% — spent retracting outriggers, moving mats, traveling, and re-setting. Case Study 18-2 shows a week where eight moves consumed 28.2% of crane capacity and $14,048. C and D are deliberate and both earn their place.

C. The notice requirement is not bureaucracy — it is the entire enforceability of the clause. Without it you have a disputed setoff that sits in the pay application for months and gets bargained away in a change-order negotiation. One time-stamped email naming the area and the deadline converts a squabble into a recovery.

B. Excusable means no liquidated damages — saving 12 × $5,500 = $66,000 of exposure. Non-compensable means you eat the extended general conditions: 12 × $5,150 = $61,800. Roughly half your daily exposure is covered and half is not, and you get none of it without daily reports establishing which controlling activity stopped and why no other work was available.

C. The facility's infection prevention team performs the assessment, crossing construction activity type with adjacent patient risk group to set a precaution class. The contractor executes and documents — barriers, negative pressure with HEPA-filtered exhaust, tacky mats, dedicated routes and carts, and a daily signed pressure log.

C. 210 × $66.00 = $13,860 per hour, against a daily schedule exposure of $10,650/CD. One hour of everyone standing still costs about 30% more than a whole day of finishing late. That comparison is the reason the superintendent's morning walk exists.

False. It lands on them first, which is why GCs miss it. Kestrel still paid $4,992 of laborer time and $2,243 of other trades' hoist delay in cash. Then it returns as lost information flow, crews quietly getting smaller, and a higher bid on the next job.

False. JIT is usually right on a congested site, but it buys handling savings with supply-chain risk. The correct answer is almost always a partial buffer sized to the failure you are actually worried about — on Northgate, one week of curtain-wall units.

False. They accumulate in whichever direction they happen to point. Four acceptable deviations can produce a nine-sixteenths-inch problem, which is the difference between a door that swings and one that binds. Re-establish from control at each stage rather than measuring off the last thing built.

False — or at least badly incomplete. Sail area matters more than weight. A 14,800-pound precast panel and a 6,200-pound curtain-wall bundle are both large flat objects; both come down well before the machine's own limit. The limits are on the load chart and in the manufacturer's manual, and OSHA's cranes standard for construction requires operating within manufacturer procedures.

False, and the distinction matters. Housekeeping is a leading indicator of planning. Debris accumulates where nobody decided who owned the area; a clean floor is a floor where someone assigned zones, sequenced trades, planned material, and scheduled waste removal — and those cause productivity. When a superintendent sees a filthy floor she is reading a report, not resenting a mess.

Unloading method reveals resource conflicts — it is where you discover that three subcontractors have all assumed they get the crane at 9:00. Destination (floor and zone) reveals whether the delivery has a plan at all. A delivery with no destination will be unloaded wherever there is room, which is not where it installs, which guarantees a second handling. Reject the request until the field is filled in.

In order: (1) anything with a truck already rolling; (2) anything blocking a life-safety route loses, immediately; (3) direct-to-install beats laydown; (4) a crew on site and waiting beats a crew not yet mobilized; (5) critical path beats float; (6) when genuinely equal, the most-recently-bumped goes first.

Number 6 is not sentimentality. It is how you keep foremen submitting honest delivery requests. If getting bumped has no memory, every foreman learns to pad their request, and then your schedule is fiction.

A worker on level 4 walking down four flights and 300 feet is gone about 12 minutes instead of 4 — 8 extra minutes. Across 210 workers at one trip per day: 210 × 8 ÷ 60 = 28 MH/day × $66.00 = $1,848/day, or $184,800 over a hundred days. That exceeds the entire budget for temporary water, sanitation, and lighting combined. The mechanism is travel time multiplied by frequency — the same mechanism that makes floor staging worth 23.7%.

1. The mixers and the gate (2 + 1 together). A truck at the gate with no window puts a mixer in the street. Concrete has a discharge clock; a rejected load is $206/CY of material plus a stalled pour and a possible cold joint that a structural engineer will have to evaluate. Send the flatbed away or stage it off-site — this is the only item on the list with a chemical deadline.

2. The crane/pour conflict (5). It does not hurt at 6:40, but the decision has to be made at 6:40, because by 10:00 there is no decision left — only a crane sitting or a pour interrupted. Move the pick to 11:45 and tell the foreman now, not at 10:00.

3. The mason crew (3). Eleven people at roughly $70/hr loaded is about $770 an hour, cash, right now, and it is the only item bleeding continuously. It ranks third only because the first two carry defect and cascade risk.

4. The inspector (4). Two hours away, but the preparation is now: confirm the area is ready, the work is uncovered, and somebody is free to escort him at 9:00. Frank Petrosyan does not wait and does not come back the same day; a missed inspection costs a day of cover-up, which is $10,650 only if it is on the critical path — know which it is.

5. The gate itself, as a system. Item 1 will happen again tomorrow unless somebody changes the delivery procedure today. That is the only item on the list whose fix is permanent, and it is the one that never gets done.

Something close to: "Eight moves last week is 12 hours — 28% of the crane's available time spent traveling, not lifting, at $3,720 plus about $10,300 of three trades standing around. We don't have a capacity problem; we have a position problem, and a second crane at Pad B blocks the east drive during two topping pours and requires a multi-crane lift plan and a full-time lift director. Eleven weeks of a second crane prices at roughly $252,500. Resequencing Cordova's erection to run each elevation continuously, moving Summit's roof loads to six Saturday pick days, and putting Crossline's level-2 units on the hoist prices at about $88,600 and cuts us to two moves a week. I'd like to run the resequence for two weeks and bring you the crane-move count on the 15th; if it isn't under three a week by then, we buy the crane."

The structure matters as much as the numbers: diagnose the resource's actual time use, price both options, name the non-monetary costs, and put a reversal trigger with a date on it.