What was being recorded, and how?
The job was injection in two caverns on a civil construction project, and it had two kinds of work. One was the slab joints: joint trenches in the cavern slabs, 13 in each cavern and 26 in all, injected through packers along each joint. The other was the injection hoses, grouped in boxes along the cavern walls, each box holding a number of hoses that are tested and injected one by one. Both were being recorded on paper checklists filled in underground, where a shift means hours with no signal. The client's checklist was the record, so whatever replaced it had to produce the same document, and it had to be at least as quick to fill in as a pen at the joint. The litres injected also had to be accounted for against the product canisters opened on site, which on paper meant adding it up afterwards.
How was DEFECTED adapted in five days?
By reusing what the tunnel app already did and building only what the caverns needed. Sign in, offline working, photo capture and upload, and the daily report came straight from the app running on tunnel projects, so none of that had to be written or proven again. The new part was a cavern module, kept separate from the tunnel records with its own tables, its own storage on the phone and its own screens, so nothing in it could affect a live tunnel project. It started from a plan of the two caverns traced from the site drawing, with every hose box and joint trench placed on it. Work began on 30 August 2026, and on 4 September the app was on a phone underground being used on a shift. The workflows kept being refined against real shifts after that, as the crew used them.
How are joints and hoses recorded underground?
In passes, which is how the work is actually done. A pass is one round of the pump along a joint's packers, and the crew logs it packer by packer as they go: the litres into each packer and the outcome, such as product coming out of the joint or at another packer, or a pressure being reached. Packer actions such as redrilling are recorded against the packer too. A long press on a trench on the cavern plan marks it in progress. Hoses follow the method for hoses. Before a hose is injected the crew water-tests it, recording whether it accepts water and whether water comes back out of a neighbouring hose, with a photo and the person. Each injection pass on a hose records the kit, the litres, a photo, the pressure at the end and the reason the pass stopped.
- Hose boxes and slab joint trenches placed on the traced cavern plan
- Water tests before injection, with a photo and who did them
- Passes logged packer by packer, with litres and an outcome for each
- Pressure and the stop reason at the end of each hose pass
- A box the crew cannot get to is recorded as no access, with a note
How are litres traced to the canister?
Every litre is logged against the kit it came out of, and the kit belongs to the litre rather than to the pass. If the crew switches canister halfway along a joint, the next lines simply carry the new kit, so a pass can draw on two kits and the record stays exact. All of these lines go into one consumption ledger, and every consumption figure in the app reads from that ledger and nothing else: the quantity on a box or a joint, the running total for the day, the consumption screen, the dashboard, the daily report and the checklist PDF. That is what makes the numbers agree from one screen to the next, and it means product use can be reconciled against the canisters opened on site without a separate tally. The kit itself follows the same model as on tunnel projects: opened with its product and batch, used, then finished.
What evidence comes out at the end of the day?
The client's own checklist, rebuilt. The daily injection checklist comes out as a PDF laid out like the client's paper form: the header grid, the checkboxes, the injection record table with its units row, an additional comments box and the sign-off box, with the form's own issue date and revision number in the footer. It is one file per day, listing every injection record of that work date across both caverns, followed by a colour reference map page for each cavern worked. Any box or trench can also be exported on its own as an evidence sheet, with its passes, packers, litres and photos. Every one of these documents is drawn by the same renderer, so the single-item sheet and the daily PDF cannot drift apart in content or layout.
What carried over from the tunnel app?
The parts that are hardest to get right underground. Records are saved on the phone first and sent when the phone finds signal, through the same outbox the tunnel crews use, so an open pass survives the app being closed with no signal and a retry can never create a duplicate. Photos are captured with their time burned in and wait on the phone until they upload. Because a shift in the cavern is hours without signal, there is a step for getting ready: before the crew walks in, the app loads everything the underground screens need, checks it actually reached the phone's own storage, and then says plainly whether the phone is ready for the shift or not. Sign in and the daily report work as they do on tunnel projects. The cavern plan and its workflows were built for this job.
Running a different kind of injection?
The tunnel side of DEFECTED is described on the tunnel defect register page and in injection records. For a tunnel deployment, read the Sydney Metro West Portion 1 case study. If your work is recorded on paper today, start a 14-day pilot and tell us what the checklist looks like.