ALBERTO ALEMÁN ZUBIETA

Alberto Alemán Zubieta, a backhoe dredger, is the latest addition to the fleet of the Panama Canal Authorities. The backhoe dredger, designed and built by IHC Merwede, will initially be used for the expansion of the Panama Canal and subsequently for its maintenance. This is not the first vessel that IHC Merwede built for the Panamanian fleet, as it was preceded by the delivery of Quibian 1, a cutter suction dredger, in 2010.

The contract between the Panamanian Authorities and IHC Global Production was signed on 9 April 2011 and the keel was laid on 13 December 2011. For the occasion of building this, the ‘prospective world’s largest’ backhoe dredger, IHC Global Production, part of IHC Merwede, formed a partnership with the shipbuilders NMC. The backhoe dredger was named Alberto Alemán Zubieta, after the former CEO of the Panama Canal Authorities. IHC Merwede launched the dredger on 31 August 2012, whilst the naming ceremony took place at the NMC shipyard in Nieuw-Lekkerland, the Netherlands, on 28 September 2012.

The naming ceremony was performed by Ana Matilde Alemán, the wife of Alberto Alemán Zubieta. A large delegation from the Panama Canal Authorities attended the event, including the current administrator Jorge Quijano, the deputy administrator Manuel Benitez, the head of the dredging division Rogelio Gordon, the project manager, engineers and the captain of the backhoe dredger.

Autoridad del Canal de Panamá and Alberto Alemán Zubieta

The Panama Canal Authorities, or in Spanish ‘Autoridad del Canal de Panamá’ (ACP), is the agency of the government of Panama responsible for the operation and management of the Panama Canal. The ACP took over the administration of the Panama Canal from the Panama Canal Commission on 31 December 1999, when the canal was handed over from the United States to the Republic of Panamá.

Because of its unique nature, the ACP has financial autonomy, as well as ownership of the canal’s assets. The Administrator and Deputy Administrator head the ACP under the supervision of a Board of Directors. The Administrator is the highest-ranking executive officer, as such the legal representative of the Authority and is responsible for its administration and the implementation of the policies and decisions of the Board of Directors. The Administrator is appointed for a seven-year term and may serve two terms at most.

After serving two terms, Alberto Alemán Zubieta stepped down in September 2012 to hand his title of Chief Executive Officer over to Jorge L. Quijano. In honour of Zubieta’s achievements for the ACP, it was decided by his successor that the new ‘world’s largest’ Panamanian backhoe dredger would be named Alberto Alemán Zubieta.

IHC Global Production

All IHC Merwede units are broken down into three divisions: dredging, mining and offshore, for which IHC Global Production delivers innovative vessels, advanced equipment and life-cycle support. IHC Global Production combines the specialised knowledge of the various companies within the IHC Merwede group. IHC Global Production provides consultancy and project management services for a wide range of products and services. They can perform feasibility studies, basic and detailed engineering of new or existing dredging equipment or product management and delivery of special dredging equipment. They are also specialised in project/ build management of dredging equipment and offshore vessels at yards outside IHC Merwede across the globe.

For Alberto Alemán Zubieta all the above mentioned aspects were called upon, though the location was not ‘across the globe’, but at NMC only a stone’s throw away. NMC is headquartered in Nieuw-Lekkerland at the waterside of the river Lek and an ideal building location nearby the other IHC Merwede facilities. The company offers all the necessary facilities for building ships or offshore and industrial equipment. All equipment and hardware were delivered by IHC Merwede companies, whilst the design and drawing office was composed from IHC Merwede’s own resources.

Productive life after delivery

Due to the nature of the contract, the job was not finished for IHC Global Production when the vessel was finished and handed over. Mid December 2012 the vessel was transported to Willemstad, the Haringvliet for sea trials. After successful trials Alberto Alemán Zubieta

IHC Merwede dredger assures Panama Canal
will remain the leading interoceanic waterway

was shipped to Panama, a journey of almost three weeks, where it started another month of acceptance trials, instructions and training for the crew. Since the end of February 2013 the vessel is fully operational in the expansion project of the Panama Canal. After this phase of expanding the Panama Canal has been finished, the vessel will be in use for maintenance of the canal and available for expected future expansion plans (like deepening).

Dredger characteristics

The vessel has been designed and built using the latest developments in technology. The width of the pontoon is relatively large compared to similar dredgers, to comply with the required stability demands of the dredger equipped with an even bigger excavator, the Komatsu PC8000. The improved design results in extremely high stability, shorter cycle times and therefore higher production rates.

The most important piece of equipment on the backhoe dredger is the hydraulic excavator, which has the capacity to dredge to a depth of 19.5 metres underwater. Its primary task will be cleaning up the debris after drilling and blasting works. This debris consists of rocks with an average size of approximately 30 centimetres square, but with a maximum size up to one metre square, which is the reason for the immense dimensions of this backhoe dredger and its excavator. The rocks will be loaded onto barges and transported to various locations. In the past, for example, the debris was used to connect an island to the mainland (the peninsula known as the Naos Island Breakwater). Another important use for the rock spoil, was for building a dam (near Gatun along the banks of the Rio Chagres). Furthermore, the vessel is due, in five or six years time, to be fitted with a larger excavator currently being developed.

Excavator design

The backhoe dredger is equipped with a modified diesel-hydraulic Komatsu PC5500 excavator. This provides a maximum dredging depth of 19.5 metres with a 13.5 cubic metre bucket at delivery. However, the vessel has been designed to be equipped with an even larger excavator in the future: the modified Komatsu PC8000, making it world’s largest backhoe dredger. With its current characteristics, the dredger still ranks among the top three of large backhoe dredgers.

The modified excavator, originally designed for onshore mining activities, was delivered and installed by Kundt Service GmbH. Kundt in fact only use the body of a Komatsu backhoe (super) shovel and upgrade all electrical, mechanical and hydraulic parts for use in marine environment. The excavator is operated from an extremely luxurious and spacious integrated cabin. The cabin is double air-conditioned and includes an air suspension seat with reclining backrest. A lot of attention has been paid to noise reduction, sound absorption and decreasing vibration at the operator’s seat.

The hydraulic power plant consists of two main drives, each powered by a dedicated Cummins diesel engine of 1,000 kW. Each diesel engine directly drives three identical main pumps, through a gearbox, which draw hydraulic oil from an unpressurised hydraulic tank. The dual circuit hydraulics system provides maximum cooling efficiency and optimised multiple filtering. In the current configuration the hydraulic power plant is located inside the body of the excavator. However, when the dredger is upgraded with the larger excavator, the diesels will be relocated inside the hull of the vessel and the excavator will become diesel-electrically driven. For now the current engine room seems extremely oversized, but in fact all preparations and space reservations have been made for this future conversion.

Moving around: assisted propulsion and walking

The vessel has no main propulsion package, but a general power plant consisting of two generator sets. The two generators, driven by marine diesels, generate the ship’s power and feed the electrical systems. In addition one harbour generator set, also driven by a diesel engine, completes the power package.

Whilst the platform has enough buoyancy to float and can be fully self supporting, its propulsive capacities are not suited to moving through the water over longer distances. In this instance it will be towed by tugs as the dredger is suitable for unrestricted and unmanned deep sea towage, with spuds lifted to the highest position. During dredging operations, the dredger is positioned on three spuds, one forward in a sliding spud carriage and two in fixed guides little aft of amidships. The backhoe dredger is designed to perform dredging operations at maximum digging depth, while standing on its stabilising spuds with the pontoon slightly lifted out of the water. For moving the pontoon/dredger a sliding spud carrier, with a net stroke of approximately eight metres is installed, operated by winches below deck. The drums, on which the wrist size cables are manipulated, are provided with special disc brakes instead of the normal band brakes. Each spud has the impressive dimensions of three metres by three metres.

For propulsion assistance and manoeuvring purposes, the dredger is fitted with two hydraulically driven, well-mounted azimuth thrusters mounted in the bow of the dredger. For manoeuvring by spud with thruster assistance, the hydraulic pumps of the excavator are used. In this situation the bucket is put aground and the hydraulics are released; all dedicated dredging hydraulic power is then diverted to provide the spud (lifting) winches, spud carrier winch and the thrusters. To support the ‘small’ deck equipment (one larger plus two smaller deck cranes and mooring winches) a separate hydraulic power pack is provided, which can also serve as emergency unit for spud operations.

Accommodation

Alberto Alemán Zubieta has day accommodation only for ten persons to operate shift work around the clock 24/7. Overnight accommodation is only provided for the captain and chief engineer, both have their own single berth cabin. Furthermore the accommodation consists of two galleys, two mess rooms, an office, operational bridge, two washing/changing rooms and stores. Separate galley, mess and changing facilities are available for the crew and officers. The wheelhouse comprises an extensive package of navigation, communication and dredging equipment. The nautical equipment is provided by IHC Drives & Automation (IHC D&A), part of IHC Merwede. The waste management consists of a biological sewage treatment without any residue.

Deck equipment

Deck equipment consists of one larger and two smaller deck cranes. Four bollards are fitted on port and starboard sides for mooring and general purpose work. For heavier tasks, like dredging and towing, six larger bollards are fitted, two on the aft deck and four on the foredeck. In addition several mooring winches are provided. This extensive amount of mooring equipment, of course, is not only for mooring the dredger along a quayside, but also for manoeuvring the 5,000 cubic metres dump barges alongside the pontoon. Normal configuration while dredging is one empty spare barge moored to the bow and one barge being filled along the port or starboard side. The later one being shifted forward or aft depending on the required filling by the excavator. A work-air compressor is provided for powering the necessary tools. The required mob boat is on starboard side fore, installed in the matching davit installation. Life rafts are positioned on port as well as starboard side. All drive shafts and discs/drums are delivered by IHC Parts & Services (IHC P&S), also part of IHC Merwede.

Tom Oomkens