Borehole location plan revisions, without the redline pile
Borehole location plan revisions pile up as soon as the rig mobilizes. A branch-and-merge workflow keeps the issued plan clean while the layout moves.
- #geotechnical
- #site-investigation
- #version-control
- #cad
A borehole location plan is issued, stamped, sent to the drilling contractor. Then the rig mobilizes and reality starts editing. BH-03 lands on a buried duct the utility search missed. The farmer won't grant access to the field with BH-07 and BH-08 in it. The client reads the first logs and wants two extra holes by the substation. None of this is anyone failing; it's what site investigation is. But it means borehole location plan revisions arrive weekly, sometimes daily, and the way most teams track them has not changed in thirty years.
Why borehole location plan revisions get messy
The traditional control is a drawing control sheet and a revision letter: Rev B issued for tender, Rev C after the walkover, redlines faxed, sorry, emailed in between. It works while changes are slow and single-file. Fieldwork is neither.
The engineer on site marks moved holes on a PDF. The office moves holes in CAD for the client's scope change. The contractor is drilling to whichever version reached them last. Now there are three current plans, each partially right, and somebody's Friday disappears into reconciling them. The failure isn't the rev letters; it's that between issues, parallel edits have no home. Everything lands on markups that must be merged by hand into one file that only one person can safely edit at a time.
Start from the site plan you already have
In BranchCAD the base drawing starts the way most investigation drawings start: with somebody else's site plan. Drop the client's PDF in as an underlay, scale it into position against a known dimension, and draft the exploration layout over it in the browser. If the topo arrives as a DXF instead, import it directly; DWG works too. No tracing from a screenshot, no waiting for a CAD seat to free up.
That gives you one live plan drawing, not a folder of exports. Everything below assumes only that.
Branch the re-layout, keep the issued plan clean
The move that changes the week is the same one software teams use: the issued plan is the main line, and every proposed change happens on a branch.
Access refused on the northern field? Branch, shift BH-07 and BH-08 to the verge, and share the branch, while the plan the contractor holds stays exactly as issued. The field engineer and the office can edit the branch together in real time instead of trading markups; the drawing is in a browser, so "the laptop with AutoCAD" stops being a bottleneck at the site cabin.
When the client signs off on the re-layout, merge. The branch's changes land on the main plan as a new version, and that version becomes Rev D. If the office had meanwhile moved one of the same holes on main for a different reason, the merge flags that hole instead of silently overwriting one decision with the other, which is exactly the collision the three-PDF workflow never catches. (What a merge conflict looks like is its own post.)
Rejected proposals cost nothing: delete the branch, the plan never carried it.
The paper trail geotech actually needs
Geotechnical work answers to reviewers, checkers, and sometimes lawyers, so the history matters as much as the geometry. Every edit is recorded: who moved BH-07, when, on which branch, and who merged it. Any issued state can be restored in one click when someone asks what Rev B actually showed. And the merge step doubles as a hold point: nothing reaches the issued plan without passing through it, which pairs naturally with a branch-based drawing review if your QA wants a named approver on every revision.
This is ordinary branching and merging applied to one document type; the pillar post covers the mechanics in full.
What BranchCAD doesn't do
Honesty section. BranchCAD is general-purpose 2D CAD. It doesn't model strata, manage lab results, or generate borehole logs; tools like Civil 3D's geotechnical module or a dedicated log manager own that ground, and plenty of teams run one alongside. What BranchCAD owns is the plan drawing itself: drafted in a browser, versioned like code, safe to edit in parallel. DXF export means the approved layout travels back to whatever the rest of the toolchain expects, and plot-to-PDF covers the issue set.
Version history and restore are on the Free plan, with 30 days of history; branching and the advanced diff are Pro. The plans page has the details, or open the editor, underlay a site plan PDF, and move a borehole on a branch. If your last investigation ended with three versions of the truth, you'll recognize what that fixes.