Ship Lock as General Queuing System with Batch Arrivals and Batch Service

The real lock operations with ships and barge convoys areconsidered dependent on the transport technologies applied, ormore precisely, the kinds of ships/convoys requiring thelockage. The fleet can be divided as follows: (1) groups of singleships, (2) pushed and pulled tows of barges and (3) differentcombinations of previous systems (1) and (2). The groups ofships and tows passing through the lock have extremely stochasticcharacteristics thus forming various arrivals and setvicetime patterns. It means that uniform navigation or strongscheduling between locks and lock operations are not possibleeven though highly sophisticated equipment is at disposal.Therefore, in this paper an analytical method was developedusing bulk queuing systems for the analysis and planning oflock requirements supporting it with numerical example. Thedeveloped methodology can be applied to determine the meanqueue length of ships - convoys at lock anchorage, withoutblocking behaviour between upstream and downstream navigationfor single-lane traffic.