Most monitoring devices perform well on a two-week domestic route. The interesting question is what happens on a ninety-day multi-modal international move, because that is where high-value equipment travels and where claims get expensive.
The failure mode is a gap, not an error
Powered loggers do not usually fail loudly. They run down, sleep to conserve charge, lose signal in a steel hold, or come back from a cold leg with an interval missing. The data you do have looks fine. The problem is the interval you do not have, and in a dispute, that is reliably the interval someone wants to ask about.
What continuous mechanical recording changes
- Unpowered G-force sensing. The sensing mechanism needs no battery. A battery powers the motor that advances the chart. The RM-3WE uses a quartz DC stepping motor powered by a single C cell; check the battery before deployment.
- No signal dependency. Sealed containers, ships' holds, RF-restricted cargo, none of it interrupts a stylus.
- Plan for the route. Select the chart duration and check the chart-drive battery and operating conditions before a long transit.
- Custody is legible. Because time maps to position on the chart, an event can be placed against the routing and therefore against a leg.
Run both, if it helps
None of this is an argument against trackers. Visibility during transit is genuinely useful, and a tracker does it well. Many of our customers ship with both: a tracker for “where is it now,” an Impact Register recorder for “what happened to it”, the second being the one that still has an answer ninety days later.