F01 · Foundation · 3–4 hours
Design basis and calculation register
Set up a design-basis statement, source register, assumptions schedule and calculation revision record the way a Singapore engineering office expects.
Tool: No calculator (lesson/checklist) · Lesson: Drafted awaiting review · Example: Not started · Workbook: Not started · Assessment: Not started
Outstanding before release: Structured report template and register checker to be built; lesson content drafted, awaiting trainer review.
Sources
| Role | Source | Note |
|---|---|---|
| Primary | LTA CDC A3 cl. 1.2 STANDARDS | Standards hierarchy (mapping awaiting checker verification) |
| Primary | LTA CDC A3 cl. 1.4 DESIGN CALCULATIONS | Design calculations (mapping awaiting checker verification) |
| Primary | LTA CDC A3 cl. 1.4.2.4 (body clause — spreadsheets: version identification, hand verification, formula printout with cell references) | Spreadsheet verification requirements (mapping awaiting checker verification) |
| Contextual | LTA CDC A3 cl. 1.4.3 SI Units | SI units (mapping awaiting checker verification) |
| Contextual | LTA CDC A3 cl. 1.4.4 Language | Language of documents (mapping awaiting checker verification) |
"Primary" marks the governing clause for this exercise; "contextual" marks related clauses; "supporting" marks the design-method or data source outside the CDC. A CDC chapter mapping does not mean the CDC contains the equation used.
Prerequisites: none · Topics: Design basis, Drawings and reporting
Lesson
Lesson draft v0.1 — awaiting trainer and technical review.
Before any number is calculated, a Singapore engineering office expects a short design basis: what is being designed, to which documents and editions, under which assumptions, and how the calculation will be checked and revised. Reviewers read this first. A calculation without it is usually returned with comments before anyone looks at the arithmetic.
Learning outcomes
- Write a one-page design-basis statement for a small element or temporary works item.
- Build a source register that records document, edition, clause and date checked.
- Separate source-prescribed values, project choices and your own assumptions in an assumptions schedule.
- Keep a calculation revision record that a reviewer can follow.
Model, assumptions and limitations
The design basis answers four questions: scope (what is in and out), criteria (which documents and which editions govern), inputs (drawings, site data, client requirements) and verification (who checks and how).
The source register is a table. Each row is a document actually used: title, issuing body, document number, edition or revision, issue date, the clauses used, and the date you confirmed it was the edition required by the contract. "Latest" is not the same as "applicable" — the contract decides.
The assumptions schedule lists every value you chose rather than read from a source, why you chose it, and what would change if it were wrong.
CDC A3 section 1.4 sets expectations for design calculations, including spreadsheet verification (1.4.2.4), SI units (1.4.3) and English as the language of documents (1.4.4). Read those clauses in the official PDF; this lesson does not reproduce them.
Design-basis extract — training example (all project details are fictional)
- Element: precast drainage culvert segment, Project "Training Road T1" (fictional).
- Criteria: LTA CDC Civil & Structural Works, Rev A3 (Dec 2025) as stated in the fictional contract; supporting Singapore Standards as referenced by CDC 1.2.
- Assumption A1: concrete unit weight taken from the project design basis report — to be confirmed with the client.
Assumed for training. Not a real project.
Common mistakes
- Writing "latest code" instead of a specific edition and date.
- Mixing assumed values into the inputs list without marking them as assumptions.
- Spreadsheets submitted without a version number or a hand check of the results.
- Revising a calculation without recording what changed and why.
Interpretation questions
- Which items in your register would change if the contract specified CDC A2 instead of A3?
- Which of your assumptions has the largest effect on the result, and how would you confirm it?
Technical English task
A reviewer comments: "Source of concrete density not stated." Write a two-sentence reply that states the source you will use and how you will update the calculation.
Burmese explanation: awaiting reviewed translation.
Calculator
This module is a lesson and checklist. It has no numerical calculator. Structured report template and register checker to be built; lesson content drafted, awaiting trainer review.
Exercises
Assessment in preparation.