305 — Crane, capacity and the pick simulation¶
Band 300 · cv-web · Cast mode
Construction order is not a detail you settle on site. The order panels come off the stack decides how far the crane swings, how often the rigging changes, and whether a panel is reachable at the radius it has to be picked from.
Cast mode is where that order is decided, and the pick simulation is where it is scored.
Warning
Crane stations and the slab edge — read this before copying any station shown here.
A crane station must sit entirely outside the wall-clearance standoff, on prepared subgrade, or entirely inboard of the closure strip, on the poured slab. Never between the two, and never spanning the boundary. The test is the machine’s bearing footprint — its tracks or outriggers — not the centre of a drawn circle. One track on poured slab and one on unpoured subgrade gives differential support under the mat; the slab edge spalls or the subgrade settles, and the machine goes out of level under load.
TCA Safety Guideline v13.1 (June 2013) §2 item 6, p.8: “Install entrance and exit ramps for the crane to position itself onto the floor slab. Do not allow the crane to exert its weight on the extreme edge of any portion of the slab.” See also OSHA 29 CFR 1926.1402 — ground conditions; the operator must be notified of bearing capacity, and the controlling entity is responsible for adequate site preparation.
Station placement in this release is a known open defect (CV-2714). The perpendicular standoff is a fixed value that every catalogued machine’s bearing footprint exceeds, so a generated station can straddle the boundary. Do not copy a station position from this lesson, or from its video, onto a real site. Have the setup reviewed against the machine’s bearing footprint and the site’s own closure-strip and brace-line dimensions.
And on this release the drawn frame can be mirrored, which makes an inside/outside verdict untrustworthy whenever it happens. It was measured in coordinates on a saved post-draw drawing rather than inferred: after Site Drawing Options is entered twice, wall-line ends land at the exact Y-mirror of their shipped positions – same X to the hundredth, Y negated – 622 feet apart at the widest, while a point at the origin separates by zero, which is what distinguishes a mirror from a constant shift. Two points were left unmoved, so this is a partial redraw and not a blanket transform of every coordinate. The no-flip control has since been run, and the frame flip IS the cause. An otherwise identical take with no Site Drawing Options entries drew ZERO mirrored points, with all four shipped points unchanged, while the flipped take mirrored two of them. The control was not a null run – it drew ten points against the shipped four, and left fourteen wall-line ends open against the shipped two – so the zero means something. The mirror is therefore not present on an untouched drawing – but the action that brings it on is smaller than it sounds: opening Site Drawing Options twice and then drawing is enough. Measured on the dialog itself, BOTH openings were closed with Esc – no OK, no edit, nothing typed. Backing out of the dialog still sets it. That is still ordinary use and still a defect, but it is narrower than the previous wording implied. The discriminator is clean and the sample is small – four shipped points, on staged copies rather than customer files. An earlier version of this note said the draw refused and therefore nothing reached the sheet; part of it drew, and what drew is mirrored.) So a station reported as clear of the closure strip may not be. Treat every crane position here as illustrative of the workflow only, never as a sited answer.
Scope, measured 2026-09-16: the footage on this page shows cv-web Cast-mode capacity rings in the casting yard, not stations placed on a site plan – 28 sampled frames across the four crane videos, none showing a slab edge or closure strip. The placement defect above is in the site-plan sequencer, so it is a caution about the workflow you are learning, not a statement about a picture on this page.
Note
This lesson also exists in the browser. Work it in ConstructiVision on the web — same steps, same values, so you can follow either and end up with the same panel.
Getting there¶
Cast on the mode bar, or Edit → Cast Layout.
What Cast mode gives you¶
control |
what it does |
|---|---|
Capacity rings |
draws the crane’s rated radii, so you can see what it can lift where |
Pick order |
the sequence panels are erected in |
Pick animation |
plays the sequence back |
Install arrows |
shows each panel travelling from stack to final position |
Wall clearance |
how close the layout may sit to the wall line |
Crane excl. |
the exclusion zone the crane body occupies |
Capacity is a function of radius, not just weight. A panel the crane lifts easily up close may be beyond it at reach, which is why the rings are drawn rather than reduced to a single tonnage figure.
Scoring an order¶
Pick Simulation runs candidate orderings and ranks them. You can start from Project order, Heaviest first, or Lightest first, and compare.
The report scores each ordering on criteria you tick — arm rotation, rig changes, and others.
Note
Some criteria cannot rank an ordering, and the product marks them “same for every ordering” rather than letting you sort by them.
Total weight is a sum over the panel set, and maximum pick radius is a max over it. Both are unchanged by the order you do the work in, so no amount of data makes them discriminate between two sequences.
Others are inert only for your job — one crane position may yield zero crane moves for every ordering, so that column ranks nothing here while ranking usefully on a different yard.
On the sample building the report ranks six candidate orderings against eight criteria — and marks six of the eight as unable to rank them. Only two columns actually separate one ordering from another. That figure is for this project; a job with a different crane position or a wider spread of panel weights will have more criteria that bite.
That marking is worth understanding, because scoring by a criterion that reads identically for every candidate feels like analysis and is not. It was added after a published frame of lesson 27 was reviewed and found to be teaching viewers to rank by a column that read the same value for all six algorithms.
What this lesson does not show¶
Running the simulation uses your AI allowance. It runs on our servers, not in the browser, and needs the AI entitlement on your organisation.
The numbers you see are for the sample building. Yours will differ.
In cv-cad¶
The equivalent lives under Site Options. The two products score the same way; the browser has no sheet border and no AutoCAD dialogs.