TKPH Calc support
Will the tyres take the heat?
About
TKPH Calc computes site TKPH/TMPH (ton-kilometre per hour) per axle for off-the-road haul-truck tyres and checks it against the tyre's rating using the manufacturer's published correction method. It runs entirely on the phone. There is no account, no server and no subscription.
Features
Calculator
- Truck: empty weight, payload, front-axle share when empty and loaded, tyres per axle. 22 presets from OEM spec sheets, or your own
- Haul: round trip, cycles per shift, working hours, ambient temperature. Optionally separate loaded and empty legs
- Tyre: rated TKPH, method (Michelin-style, Bridgestone-style or Generic), construction and section width. Add your own tyres under Tyres
- Result: verdict (OK under 90 %, Marginal 90 to 100 %, Exceeds over 100 %), margin, per-axle figures and the governing axle
What-if and compare
- What-if solves for the maximum cycles per shift, payload or average speed at a target margin
- Compare shows two tyres on the same haul side by side
Sites, studies and reports
- Save a study with its site; reopen it from the Studies tab
- Share PDF makes a one-page report with every input, every step and the method used
- Export CSV writes all studies to one file
GPS cycle logger
- Calculator > Haul > Log cycles with GPS. Tap LOADED when the truck leaves the shovel and EMPTY after it dumps
- Logged legs give measured round-trip distance, cycle time and average speed, which feed the calculator
- Needs Location While Using the App; keep the app open while logging
Privacy
- Everything stays on the phone: inputs, studies, tyres, sites and GPS positions
- No account, no analytics, no ads, no crash reporting
- The app makes no network connections at all
- PDF and CSV files go only where you send them from the iOS share sheet
Data accessed
- Location (While Using the App): optional, only when you start the GPS cycle logger, to measure haul distance and speed. Positions are stored on the phone with the logged cycles and never sent anywhere
Requirements
- iPhone with iOS 15 or later
- Free. Every feature is included; there is no in-app purchase and no subscription
- Location access is optional and only used by the GPS cycle logger
Planning aid only. Confirm tyre ratings and operating limits with the tyre manufacturer. TKPH Calc is not affiliated with or endorsed by any tyre or truck manufacturer; Michelin, Bridgestone, BKT, Caterpillar, Komatsu and other names are trademarks of their owners, used only to identify the published method or product.
Troubleshooting
The result says the Michelin temperature correction is outside its range
- The Michelin-style method is defined only above a minimum average speed at high ambient temperatures. Check cycles per shift, working hours and round trip; a very slow haul at over 38 C has no defined correction
The logger does not record distance
- Allow Location While Using the App when asked, or in Settings > Privacy & Security > Location Services > TKPH Calc
- Keep the app open while logging; the logger does not run in the background
- Inside a cab, GPS can take a minute to get a fix. Legs shorter than a few metres are discarded
My tyre is not in the list
- The bundled list is a small sample. Add your own under Tyres with the rating from the manufacturer's data book
FAQ
Does anything get uploaded?
No. The app contains no networking code. Studies, tyres, sites and GPS positions stay on the phone until you share a PDF or CSV yourself.
Where do the formulas come from?
From the tyre manufacturers' public data books (Michelin Earthmover Data Book, Bridgestone OTR Data Book) and published industry references. Every coefficient in the app carries its source, and the result screen names the method used.
Can I rely on the verdict?
Treat it as a planning aid. Confirm tyre ratings and operating limits with the tyre manufacturer before changing tyres or haul conditions.
What does it cost?
Nothing. TKPH Calc is free with every feature included. There is no in-app purchase and no subscription.
How do I delete my data?
Delete studies, tyres and sites from their screens, or delete the app, which removes everything it stored.
Need more help?
If you couldn't find the answer above, write to me and I'll be happy to help: contact@techbysaurabh.com