A fixed sequence with formal gates.
Every package moves survey to as-built through the same governed sequence. Nothing proceeds to civils or handover until the LLD and the assurance case are signed. The same discipline carried the Connected London LLD packs through approval first time.
Survey
Ground-truth route, ducts, chambers, reach.
IHLD / HLD
Topology, backbone routes, service sectors.
LLD
Splice packs, channel plans, chamber layouts, BoM, civils SLDs.
Sign-off gateAssurance
Link-loss, OSNR and GSNR proven to end-of-life margin under TfL and LU assurance.
Sign-off gateAs-built
Red-line capture, handover, O&M, close-out.
How we engineer a span.
If the margin does not close, the design changes before the civils do. Moving a chamber on a drawing costs minutes. Moving one under a London street costs a traffic order.
The span method, step by step.
Four steps in a fixed order. Each one produces evidence the next one depends on.
01 · Ground truth
Survey establishes measured route, duct and chamber data. Reach budgets start from evidence, never from assumption.
02 · Event-by-event budget
Each connector, splice and fibre section carries its own loss allocation, so the budget can be audited line by line.
03 · Worst-case proof
The span is proven against end-of-life limits: repair splices, ageing attenuation and the lowest OSNR the receiver will ever see.
04 · Gated sign-off
Margins are signed at the LLD and Assurance gates before anything is committed to civils.
The design process is engineered too.
Design-rule automation and data QA run inside the production path, in IQGeo, QGIS and bespoke tooling.
Rules, encoded
Client design rules are encoded in IQGeo and QGIS tooling: splice-loss allocations, chamber capacity, naming and topology conventions applied on every span, every time.
QA in the path
Data validation and topology checks run inside LLD production, so a pack cannot leave the design office carrying a known class of error.
Clean handover
As-builts, O&M inputs and close-out documents leave the estate operable and the record trustworthy.
What lands on your desk at each gate.
Each deliverable is tied to the gate that closes on it. Nothing is promised without a document behind it.
LLD pack · LLD gate
Link-loss and power budgets, fibre allocation sheets, splice packs, schematics.
BoM / BoQ · LLD gate
Bills of materials and quantities a contractor can order against.
SLDs · LLD gate
Civils, duct and box-to-box single-line diagrams.
Method statements · Assurance gate
Migration and cutover method statements for live estates.
MoP / RFS · Assurance gate
Method of procedure and ready-for-service documentation.
As-builts · As-built
Red-line capture and as-built records at handover.
Bring us in at survey, not at rework.
A 30-minute technical call to pressure-test route, reach and margins before anything is committed to civils.