In Depth #1: TKPH

Click to Print

Definition: Tonne kilometre per hour (TKPH) is the measurement of the work load of a tyre and is based on the weight and speed that the tyre can handle without overheating and causing it to deteriorate prematurely. A TKPH rating for a tyre is the theoretical maximum workload it can take (average weight on the tyre * average speed of the truck OR more specifically, tonnes * km/h). The same principals apply to ton miles per hour (TMPH).

Example: On one axle, the truck has two tyres. The total load on the axle is 100 tonnes when the truck is loaded and 50 tonnes when the truck is empty. The average load on the axle is 75 tonnes which is 37.5 tonnes per tyre. If the average speed of the truck is 20km/h, the tyre rating would need to be 37.5*20 or 750 TKPH in order to not be a limiting factor.

How TKPH affects haulage in Spry

TKPH is calculated per schedule step. If the calculated TKPH is higher than the tyre’s rating, TKPH becomes a limiting factor. This will result in the Adjusted Cycle Time being increased until TKPH is equal to the Tyre Rating.


In order to use TKPH, first tick the “Apply TKPH Limits” on the Truck Specifications page.


Once ticked, Tyre Ratings can be added and adjusted per axle under the Axles tab.Choose from the tyre database by clicking “…”that matches the tyre size (defaults to tyres set in Specifications above)



It is important to note that the TKPH reported is the calculated TKPH, not the maximum TKPH set in your Tyre Rating.

TKPH is calculated per axle, but only the axle with the highest TKPH is reported.

Two TKPH reporting fields are available, Raw & Adjusted Maximum Tyre TKPH.

  • Raw: The calculated TKPH value before the tyre rating and truck limits are applied.
  • Adjusted: The calculated TKPH value after the tyre rating and truck limits are applied.