English to German Bus/Financial Transport / Transportation / Shipping

Und noch einmal der Dienstleistungsvertrag (Transportleistungen). Wie würdet ihr in diesem Kontext "back-and-forth-movement" übersetzen???

• The period from Saturday 22.00 hours to Monday 6 hours and the period of the day before a public holiday at 22.00 hours until the day after a public holiday at 6.00 hours, do not count as loading time or unloading time, except where work is being done on the vessel in this period. Each 12-hour period started shall count for 12 hours. A 12-hour period shall commence every time loading or unloading starts or is continued, solely where accompanied by recovery,with a maximum of four periods (as there are four free periods: Saturday 22.00 - Sunday 06.00, Sunday 06.00 - Sunday 14.00, Sunday 14.00 -Sunday 22.00, Sunday 22.00 - Monday 06.00; in the case of more than one consecutive public holiday, this maximum shall be increased proportionally)

• The increase in carriage charges per 12-hour period commenced shall be € xx/ton for push barges and € xx/ton for motor vessels up to and including the 10th period and xxx and xxx respectively from the 11th 12-hour period, except where indicated otherwise in the schedule(s).
The first recovery is included in the carriage charge. A payment in €/recovery shall be paid to the Carrier for each additional recovery, which payment we shall determine on the basis of indications in the schedule(s).
For motor vessels, the ***back-and-forth-movement*** is one recovery;for push barges, the ***back-and-forth-movement*** is two recoveries.

Vielen Dank im Voraus!
Daniel