Self-Unloader

Ambassador Refit and Repair

Owner: Marbulk Shipping Inc.
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Scope

The Ambassador, a Seaway size self-unloader owned and operated by Marbulk Shipping Inc. of Beverly, Massachusetts, entered Gdansk Shipyard in Poland in January 2003. The Ambassador has been a workhorse for Marbulk Shipping since it entered service in 1982. The time had come for a substantial overhaul and EMS-Tech was called in to prepare upgrade plans and refurbishing details.

The original mix of roller track gates and swing gates was removed and replaced with slider type centre split so called 'bulk flow' gates. In addition to this, substantial repairs were completed to the tunnel conveyors, transfer conveyors and Loop Belt elevator.

This project follows on the successful 2002 mid-life refit of the M.H. Baker III, a similarly sized self-unloader owned and operated by CSL International of Beverly, Massachusetts. The gates on the Ambassador differ from those on the M.H. Baker III only in so far as the gate moves on sliders rather than on rollers.

Both gates types are suspended from the hoppers thus eliminating the need for support structure on the tank top. Other positive features to the new gate system are: (1) two cylinders rather then four; (2) gate skewing problem has been corrected; (3) Gate synchronizing system has been added to ensure that gate halves open symmetrically about the centerline of the conveyor; (4) better movement of poor flowing materials.

In addition to the gate change, the hydraulic feed system for the gates and vibrators has also been redesigned and replaced. Steel fittings have been eliminated and replaced with stainless steel or brass units. Hydraulic vibrators were renewed and more substantial vibrator mounts installed.

Result

The Ambassador re-entered service for Marbulk Shipping in May 2003 and since that time has operated without complication and with improved efficiency.