This system operates by establishing a pivot, or relative pitch point about the bow of the tug. A clamp or caliper is deployed here, which attaches to a vertical bar at the head of the notch. Once gripped to the bar, the caliper is the pitching point. The tug has two sidepads at about midships, with either one or both moveable. The tug enters the notch with one pad retracted. The tug bow clamp is engaged and the pad(s) extended to fill the notch. The result is that the tug pitches about the bow clamp, with roll restrained by the moveable pads on the tug. The system has been in existence for many years, and BLUDWORTH-COOK is designing a new version that will eliminate many of the shortcomings found in the current design.

A simple system with light weight and easily retrofittable. The hydraulic components are fairly simple, and take up little space and power. Installation on the tug is straightforward and usually requires little in the way of structural changes and is among the least expensive to install on a tug. The system is sold and serviced by a reputable organization, and has a long history, with many applications.

Some operational flexibility is lost with this system as far as ordinary tug work is concerned. The tug’s bow unit holding the caliper can hole a barge easily if the tug comes alongside, or gets loose in the notch. The helmsman can’t see it in most cases, and it limits the tug to pushing in the notch, as opposed to working alongside, or approaching the barge from a tow in heavy weather. The system does have an 18 degree pitch limit, at which it will automatically disengage. The barge notch in the present system needs to meet very tight tolerances in construction which many yards have a difficult time meeting. The bar at the head of the notch also prevents other tugs from easily pushing the barge, and the longer notch needed as opposed to other systems, adds to barge cost. Bludworth is working on a bow unit adaptation that will allow full fendering, while retaining the functional capabilities of the system, mitigating many of the noted issues including automatic release. Note as well that this is among the most-applied systems in the marketplace. OT&BE has designed many AT/B tugs with this system, as well as multiple conversions, all of which have been successful.