Work and hours
- Jobs, job types, scheduling and dispatch
- Shifts with live duty time
- Railway hours and minimum rest limits
- Fatigue indicator with human review
- Timesheets approved by period, CSV export
Native iPhone and Android apps · early access open
Field operations for UK rail and depot work
The whole rail shift, in one record.
GuardianOS takes your crews off paper job sheets and scattered apps. Sign-on, jobs, pauses, photos, risk assessments, client release sheets, timesheets and mileage — one system, on native apps for iPhone and Android.
Rail hours and rest built inYour brand inside the appPay only for the modules you use
9:41LTE · 84%
Rail Shine02:43Saturday 29 August
Morning,
Dan
Dan
Do this next
Van check, then you are clear
Start van check
Kilburn High Rd10:00 · 1 job
12:18LTE · 71%
1:12:40Arrived 10:58 · started 11:06
EvidencePause
Evidence2 of 4
Complete job
Two more photos are needed before you can complete.
In brief
What is GuardianOS?
GuardianOS is a configurable field operations platform for UK rail and depot crews. Workers carry the native app; the office runs scheduling, live status, review and configuration from the web portal. Both use the same API, and every material action is audited — who did it, when, on which form version, and whether it happened offline.
- For
- UK rail contractors, depot operators and train cleaning teams
- Replaces
- Paper job sheets, WhatsApp evidence, manual timesheets, separate check apps
- Apps
- Swift on iPhone, Kotlin on Android, web portal for the office
- Pricing
- Core per user, plus the modules you switch on
- Made by
- Hillmorton Design & Development
How a shift runs
One day on the line, in one record.
Follow Dan, a track operative, through a Saturday. Most crews run these steps across three or four tools. In GuardianOS each one follows the last, and the app only offers the next legal step.
9:04duty hours
46miles recorded
20moff site, deducted
Sign on for duty
On dutyClock on, pick the vehicle, and see which gates stand between you and the first job. Location is recorded and encrypted.
Briefing
Read and acknowledge. A briefing can hold jobs until it has been read.
Van check
A configurable inspection. A failed item needs a photo and a note before you can go on.
Travel and arrive
TravellingTravel time and miles are recorded on the way to Kilburn High Rd.
Risk assessment
DSRA on arrival, or EDRA where no site assessment exists. Start work unlocks when it is done.
Work, pause or leave site
Paused · left siteA live job clock, and two kinds of pause the app never confuses. Leaving site means travelling back to reopen.
Photos and evidence
The job template sets what is needed. Photos taken without signal queue and send on their own.
Client release sheet
CompletedSent on a secure link to every recipient, and held back if a check fails.
Sign off, timesheet and mileage
The shift becomes a timesheet row, approved by period and exported as CSV with the miles.
12:41LTE · 70%
1:12:40
Are you staying on site?
If you leave, you travel back and arrive again before the work reopens.
Cancel
Job pause, done properly
Staying or leaving? The hours depend on it.
Waiting for a possession is not the same as driving off for materials. GuardianOS asks once, states the consequence before it is chosen, and keeps the two apart in the timesheet. Try it on the phone.
Pick an option on the sheet to see what the app does next.
Paused · stay
Work is on hold, you are still here
Resume whenever you are ready. Duty hours keep running while you wait, and the office can see this pause and its reason.
Paused · left site
There is no resume button — on purpose
Because you left site, you travel back and arrive to reopen the work. Time off site is not counted towards duty hours, and the original start time is kept.
Features
Built for the rules rail work runs on.
Your forms, workflows and job sheets are configuration, not code. Railway hours, rest and audit are protected platform rules that cannot be edited away.
Safety and compliance
- Lone worker heartbeat, SOS and stand-down
- Man-down and impact detection
- DSRA, and EDRA for unassessed sites
- Briefings that can gate sign-on
- Close calls and retrospective entry, marked late
Vehicles, depots and assets
- Van and vehicle checks
- Drive tracking and mileage
- Yard Mode: many locos in one session
- Rolling stock and asset register
- Materials used per job, stock per van
Delivery and records
- Client release sheets on secure links
- Versioned form and workflow builder
- Photo review queue
- Live operations map
- Immutable audit trail on every change
Native apps
Written for each phone. Branded for each company.
The field app is native on both platforms, so it opens fast, uses the camera and sensors properly, and stays readable at arm’s length in gloves. There is one GuardianOS app per store. Your crews enter a company code and it becomes your system: your name, logo, colours and only the modules you pay for.
iPhone
Swift · SwiftUI
Android
Kotlin · Jetpack Compose
GuardianOSCompany code
Your office gave you a code. It sets up the app for your company.
RAILSHINE
Rail ShineBranding, sign-in copy and 9 modules loaded
The home-screen icon stays GuardianOS — app stores require it. A store-level branded build is available as a paid extra.
Modules
Start with the core. Switch on the rest.
Each module is enforced on the server, not hidden in a menu. Switching one off removes access but keeps the records.
Core, always on
Included- Users, roles and sessions
core.auth - Jobs, sites, clients, job pause and leave site
core.operations - Staff directory and emergency contacts
core.staff - Shifts, timesheets, approval and export
core.workforce_hours
Safety pack
Add-on- safety.van_checks
- safety.dsra
- safety.edra
- safety.photos
- safety.fatigue
- safety.lone_worker
- safety.impact
Van checks, risk assessments, photo review, fatigue, lone worker and man-down.
Depot pack and more
Add-on- ops.yard
- ops.assets
- ops.maintenance
- ops.materials
- ops.drive_mileage
- ops.live_map
- ops.reports
- compliance.briefings
- incidents.close_calls
- documents.release_sheets
Yard sessions, rolling stock, maintenance, van stock, mileage, the live map, briefings, close calls and release sheets.
Compare
GuardianOS vs Mitti, Signal and BigChange
Inspection apps check the work. Rostering tools plan the hours. Field service tools dispatch the van. GuardianOS runs the shift in between.
| Capability |  GuardianOS | Mittiformerly SafetyCulture · inspections | Signalrail rostering and fatigue | BigChangefield service jobs |
|---|---|---|---|---|
| Running the work | ||||
| Jobs and dispatch | Yes · schedule, assign, track | No · schedules are for inspections | Partly · shift booking, not jobs | Yes · scheduling and dispatch |
| Job pause and leave site | Yes · leaving means travel back first | No · no job to pause | Not listed | Not listed |
| Duty sign-on and shifts | Yes · sign on, live duty time, sign off | Partly · Sign On add-on, paid per site | Yes · rostering and shift booking | Partly · via timesheets |
| Timesheets for payroll | Yes · approved by period, CSV | No · needs another tool | Yes · digital timesheets | Yes · reconciled with tracking |
| Drive tracking and mileage | Yes · miles exported with hours | No | Partly · travel time in fatigue scores | Yes · vehicle tracking |
| Railway hours and rest | Yes · protected limits | No | Yes · Network Rail standard | Partly · working time directive |
| Fatigue | Yes · indicator with human review | No · checklists only | Yes · real-time fatigue and risk scores | Not listed |
| Safety and compliance | ||||
| Form builder | Yes · versioned, photo and stop rules | Yes · mature, template library | Not listed | Yes · custom worksheets |
| Van and vehicle checks | Yes · failures need photo and note | Yes · via inspections | Not listed | Yes · walk-around checks |
| Risk assessments | Yes · DSRA, plus EDRA | Partly · general checklists | Partly · fatigue and exceedance RAs | Partly · health and safety forms |
| Lone worker | Yes · heartbeat, SOS, man-down | Yes · check-ins, panic alerts | Not listed | Not listed |
| Briefings | Yes · can block sign-on until read | Yes · Heads Up | Not listed | Not listed |
| Delivery and platform | ||||
| Client release sheets | Yes · secure links, held on a failed check | Partly · reports as PDF or link | Not listed | Partly · customer portal |
| Yard and rolling stock | Yes · many locos in one session | Partly · general asset register | Not listed | Not listed |
| Field apps | Yes · native Swift and Kotlin | Yes · native apps | Yes · worker app | Yes · iOS and Android |
| Your brand in the app | Yes · name, logo, colours | Partly · your logo in the Mitti app | Not listed | Not listed |
Where the others are stronger
Mitti
Scale and breadth: 80,000 organisations, training courses, sensors, contractor compliance, a public template library and a free plan for up to 10 users.
Signal
Rostering depth. It is the official fatigue management supplier to Network Rail, and shares shifts across suppliers as a master vendor.
BigChange
Commercial back office: CRM, quoting, invoicing and hard-wired vehicle tracking. GuardianOS leaves invoicing out by design and exports instead.
Sources: mitti.com and the Mitti media release of 11 August 2026 ·signalsoftware.co.uk ·bigchange.com. Prices and plans change; check before quoting.
GuardianOS × Rail Shine
Partnership
Developed in partnership with Rail Shine.
GuardianOS grew out of the day-to-day work of Rail Shine’s mobile cleaning crews. We build alongside their teams on depot and on track, so every rule in the product comes from a real shift — then make it configurable for every rail business that follows.
Shaped by their crews
Screens are tested with the people who carry them, in gloves and on night possessions.
Rules from live work
Both pause types, rail hours, EDRA, yard mode and release sheets came from Rail Shine operations.
First to move across
Rail Shine is the launch partner for the native iPhone and Android apps.
FAQ
Questions we get asked
What is GuardianOS?
GuardianOS is a field operations platform for UK rail and depot work. It replaces paper job sheets, separate check apps and manual timesheets with one record that runs from duty sign-on to timesheet and mileage export.
Does GuardianOS work on iPhone and Android?
Yes. It is built as a native Swift app for iPhone and a native Kotlin app for Android. There is one GuardianOS app on each store; a company code loads each employer’s name, logo, colours and modules.
How is GuardianOS different from Mitti (formerly SafetyCulture)?
Mitti checks the work; GuardianOS runs the shift. Mitti is strong on inspections, issues and training. GuardianOS also runs jobs, pauses, railway hours, client release sheets, timesheets and mileage — the steps Mitti users typically run in another system. Many teams keep Mitti for audits.
Does GuardianOS manage railway working hours and fatigue?
Yes. Railway working-hour limits and minimum rest are protected platform rules that cannot be edited away through the workflow builder. Fatigue is shown as an indicator with a human review step, and a held fatigue report can hold sign-on pending office review.
What happens when a worker pauses a job?
The app asks whether they are staying on site. If they stay, they can resume any time and duty hours keep running. If they leave, there is no resume: they travel back and arrive to reopen the work, and time off site is deducted from duty hours.
Does it work without signal?
The native apps are designed offline-first. Photos and forms captured without signal are queued on the phone and send on their own; nothing is dropped silently. Entries are stamped with when they happened and when they arrived, so late entries are marked for the office.
Does GuardianOS do invoicing or payroll?
No. GuardianOS records hours, travel and work, then exports approved timesheets and mileage by period as CSV. Invoicing and pay calculation are out of scope by design; accounting connectors are planned.
How is GuardianOS priced?
A core price per user, plus the modules you switch on. You can start with one depot and the modules you need first, then add more as you go. We also rebuild your most-used checklists as part of onboarding.
Is GuardianOS available now?
The GuardianOS platform is live in production with workspaces, modules, a versioned form builder, jobs, shifts and timesheet export. The native iPhone and Android apps are in build, and early access is open. The field workflow has run live at Rail Shine.
See a full shift, sign-on to release sheet.
A 30-minute walkthrough on a real phone. Bring your current job sheet and we will show it running in GuardianOS.