303 — Cast Layout, in cv-web

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.

Panels are cast flat on the slab before they are stood up, and the order they are cast in decides the order they can be picked.

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.

Cast is a mode, not a dialog

Click Cast in the top bar, beside Elevations. Its controls sit in a Layout Settings panel next to the drawing rather than in a dialog on top of it.

This is worth saying because it is easy to miss: the site work in 300–302 all lives behind the Elevations menu, so if you go looking for a Cast menu item you will not find one. Cast and Brace are modes.

What Layout Settings carries

Pick order	the sequence a crane can actually lift them in
Pick animation	plays that sequence
Capacity rings	how far the crane can reach at a given load
Install arrows	where each panel travels to
Wall clearance	the room a panel needs between the bed and the wall it is going onto

The pick order is worked out, then yours to change

The order is not just a list you sort. It starts as a walk around the perimeter — the sequence the panels come off in — and you can re-sort it by Project, Heaviest or Lightest, or drag it into the order you want.

Each pick is then checked against what the crane can actually lift at that radius, using a rated capacity curve that falls off with reach — from 300 tonnes close in to 18 tonnes at full extension.

Warning

Planning here assumes one class of crane. The capacity curve is for a large crawler (LR1300 class) and does not yet change when you pick a different machine. If you are planning with a materially smaller crane, treat a pick that passes here as not yet checked — the numbers are for the bigger machine. Tracked as CV-1988.

Why these are one problem

Pick order is not scheduling. A panel cast underneath another cannot be lifted first, whatever the programme says — the stack decides the sequence.

Capacity rings are not a preference either. A crane’s lift capacity falls off with radius, so a panel sitting outside its ring at that weight is not a slow lift, it is a lift that cannot happen. Moving it in is a casting decision, made here, not a crane decision made on the day.

Wall clearance is the room the panel needs to be stood without fouling the wall it is going onto.

Cast order, pick order and crane reach are the same decision seen three ways. This view is where they are settled — before anyone is standing on the slab.

Two views

2D to read the bed, 3D to see the stack. Same layout either way.

What to take away

Where a panel is cast determines when it can be lifted and whether the crane can reach it. That is why the casting layout is a planning tool and not just a drawing.