In plain terms: A CAD model can show what a ship looks like, but a picture alone
cannot prove a clearance, volume, or clash result. Forge preserves the chain from the
original engineering model to the number, the rule, the reviewer, and the final decision.
The difference between a picture and evidence
A 3D viewer is valuable for understanding location and context. It helps a reviewer see which compartment, component, or opening is being discussed. But the triangles used to draw a fast picture on a screen are an approximation of the engineering shape. Forge therefore keeps two related representations:
The display model helps people see the issue. The engineering geometry supplies the
evidence.
The evidence chain
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1. Preserve the source model
Forge records the imported file, its format, its digital fingerprint (a hash that
distinguishes that exact file version), its units, and how it entered the system.
For STEP assemblies, it also preserves each component occurrence and its position in
the assembly.
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2. Calculate from engineering geometry
A geometry kernel is the software that reads and calculates over the underlying CAD
shapes. It computes the requested result, such as a volume, a principal dimension,
or the clearance between two components.
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3. Create a measurement record
Forge stores the result as a measurement record rather than passing around a loose
number. The record includes the value, unit, method, source model, import, and exact
geometry objects involved. This is applied to geometry.
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4. Cite the measurement
Any formal claim such as “the clearance is 8 mm” must cite the identifier of that
measurement record. Forge can then verify that the record exists and belongs to the
same vessel and model scope.
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5. Review and sign the decision
The cited claim moves through the verification ladder and responsible human review.
Once approved, the final decision preserves the evidence chain that supported it.
Clearance, contact, and clash
These terms sound similar but lead to different engineering actions:Clearance
A positive distance exists between two components. The stored result states the
distance, unit, measured objects, and source model.
Contact
The calculated clearance is zero: the components touch. Whether that is intended is
an engineering question, so the context remains visible.
Clash
The components overlap. Forge raises a review flag rather than inventing a negative
clearance or presenting an uncertain result as settled.
What happens when the model is uncertain
Imported CAD is not automatically authoritative. Units can be missing, scale can be ambiguous, and some files require repair before they can be read. Repair can also change the shape. When that uncertainty could affect a measurement, Forge stops before creating the measurement record and identifies what needs review. Once the source or import question is resolved, the calculation can run from a known basis. This is an important trust behavior: Forge does not allow the precision of a displayed number to hide uncertainty in the model that produced it.Why this matters to different reviewers
Executives and program leaders
See whether readiness claims are supported by evidence and where review effort is
concentrated, without needing to inspect the CAD model themselves.
Naval architects and engineers
Move from a flagged issue to the exact components, measurement, model version, and
governing requirement behind it.
Class and regulatory reviewers
Follow a claim back through its cited measurement and source instead of receiving an
unexplained number or screenshot.
Yard IT and security teams
Keep the source model and its evidence chain inside the approved partner environment,
with access and processing governed by sensitivity.