feat(cookbook): freight trailer with roof solar-battery packs

[w1ne]

A 13.6 m dry-van cookbook that mounts discrete solar-battery cabinets on the roof and places them with a closed-form keep-out and axle-balance rule.

Cookbook

freight-trailer-roof-solar-batteries

The model is a full-scale enclosed box semi-trailer: chassis rails, kingpin plate, landing legs, tandem bogie, dual wheels, corrugated walls, rear doors (fastened shut), nose fairing, and side walkways. Each roof cabinet is a fastened assembly part (feet, pack, frame, laminate) shown in matte photovoltaic navy so the array reads against the white box.

How “optimal” is defined

Closed form, not a search and not a model call:

1. Keep-outs: front fairing, rear door-header strip, side walkways.
2. rowCount / columnCount default to the largest integer grid that fits those keep-outs at the default gaps (7 × 3).
3. Cabinets are identical, so the geometric centroid is the mass centroid. targetX = share * kingpinX + (1 - share) * bogieCenterX is the station that puts kingpinLoadShare of the pack weight on the kingpin and the rest on the tandem bogie center.
4. The grid is centered on targetX and clamped inside the keep-out window. layoutNote records rows, columns, target, start, centroid, clamp, and share.

FEA is not run. OCCT mass properties are not queried. Doors are closed and fastened, not a revolute mechanism. animationView scrubs gapAlong and gapAcross; it does not add or remove cabinets.

Evidence

Publish preset (studio lighting, white ground). Pixel check of the top view: seven navy spans along the roof centerline, about 134k navy pixels, against the white box.

Isometric dry van with a 7 by 3 navy roof array
Roof plan showing seven rows of navy cabinets
Side elevation of the trailer and roof cabinets

No share URL. This environment has no hosted open_in_studio hook, so the model was not published.

Tests

• tests/integration/examples/industryFreightTrailerCookbook.test.ts — evaluate_script, mechanism real
• src/agent/mcp/tools/industryFreightTrailerCookbook.test.ts — lookup hits the snippet

Left unmerged for the coordinator.

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