Sea change

10 October 2017


Service providers and manufacturers are exploring new technologies to avoid any interruptions during offshore operations, and ensure safety even in harsh sea conditions. Paola De Pascali reports.

Headquartered in Aberdeen, EnerMech works globally with over 40 locations across five main regions—the Americas, Europe, Middle East & Caspian, Asia, and Australia.

EnerMech international mechanical handling services director John Morrison says that they operate in the oil and gas, utilities and infrastructure sectors: “In the oil and gas sector specifically, we specialise in providing cranes and lifting services for the offshore industry. Offshore lifting operations are highly complex due to the extreme weather conditions coupled with the criticality of the cranes and the stringent offshore regulatory regime. Without a working crane, platform operations come to a standstill and crane uptime is critical in ensuring everything from drilling and production activities can continue, to ensuring water and food supplies can be brought on board for the crew.”

Morrison explains that planning is the key to keep any interruptions to oil and gas production to a minimum while maintaining safe operations at all times.

Recent contracts include providing crane personnel and training services for up to 70 offshore crane operators in Malaysia; a three-year management contract covering all crane operation, maintenance and inspection requirements for BP Exploration (Caspian Sea) in Azerbaijan; a three-year contract with two one-year options to provide North Sea crane operation and maintenance for Total E&P UK.

“Typical projects, which we have completed lately, include the replacement of two pedestal cranes with new state-ofthe- art machines on an offshore platform in the North Sea,” Morrison says. “This was a hugely complicated job as it was done without the use of external cranage such as a crane barge or temporary crane. A jacking and skidding option was chosen as the most cost effective.

“Amongst other jobs is relevant the overhaul of an offshore crane in the Middle East. This required some of the components to be shipped onshore for blasting and painting. As it was a single crane platform, EnerMech supplied one of our EnerLift temporary cranes, in this case a 25t stiff leg crane, to lift off the components and to provide temporary crane cover while the platform crane was out of commission.

“We got also involved in the replacement of a boom on an offshore crane in the Caspian Sea on a platform with two cranes. In order to minimise platform interruption, it was decided to change-out the 36.7m boom, which was about 16t in weight, in one piece. This required the new boom to be fully prepared onshore and shipped out on a supply boat, pre-rigged and ready to be lifted onto the crane. Through detailed planning and co-operation between a host of departments, the actual time it took offshore was reduced from the planned 14 days to 10 days from start to finish.” In these projects a variety of overhead lifting equipment was used, from 60t pedestal cranes to a 25t EnerLift rental crane. EnerLift is EnerMech’s own brand of temporary cranes that can be built up on the offshore platform deck and then demounted on completion of the job. “We offer a range of crane types including knuckle boom, lattice boom, derrick cranes, 5 to 25t SWL,” Morrison says. “Safety is always top of our agenda and although having the right equipment and processes is of course vital, the key to a successful outcome is to have motivated, highly trained and competent people involved at all stages of the project execution.”

All of EnerMech’s crane operating and riggers are trained and assessed in accordance with the latest offshore standards such as BS 7121 Pt11, API2D RP, Offshore Petroleum Industry Training Organisation (OPITO). All members of its technical staff are automatically enrolled into EnerMech’s competency assurance programme, which is run and administrated by their in-house Training Academy.

“With the downturn in the oil and gas market in recent years cost has become a main focus for our customers and we are continually working with them to find the most cost-effective solution both for the short and long term,” Morrison says. “Maximising life of assets is critical and setting appropriate maintenance campaigns can assist this. Customers are also seeking more turnkey type projects, which require the contractor to carry out everything from engineering to completion and provide cost surety. That has allowed us to become more innovative in our commercial models.

“On the lifting equipment side, we are finding there is more of a tendency to hire lifting equipment rather than buying it and we have invested heavily in a fleet of fully equipped rigging lofts for our hire fleet to service this market.”

Talking about the future, Morrison says that the second half of 2017 and through 2018 will remain steady and they forecast a new growth from 2019. “We envisage a continuing downward pressure on costs with a focus on time and cost efficiency and this is something we are addressing across all our business lines with a range of flexible commercial models, including fixed price or target cost schemes, which provide clients with cost surety,” Morrison says. “We are investing in R&D to develop smart ways of gathering and using maintenance data. This will allow us to move from the traditional time-based maintenance structure to more condition or predictivebased regimes, thus reducing costs to our customers without sacrificing reliability or more importantly, safety.”

WEIGHING UP ATEX DEMANDS

Straightpoint boasts a full range of ATEX and IECEx products, particularly suited to the offshore oil and gas sector. Director David Ayling notes increased demand from the industry, which recently manifested itself in a sizeable order for ATEX Radiolink plus load cells from a Greek oil shipping company for use aboard oil tankers.

“That was just one example,” says Ayling. “We are welcoming interest in the explosion proof range from varied sources. A commonality with these enquiries is the technical minutiae that our engineers get into with existing and prospective customers. It makes it a challenging but rewarding sector in which to immerse ourselves.”

Straightpoint is also processing orders for load pins, shackles, compression load cells and other equipment that can be used subsea that are typically used alongside exploration and drilling activities at underwater locations. Ayling cites “weekly” demand for these products as a good barometer by which to measure increased activity in the marketplace.

Orders in terms of units and capacities are varied, as Ayling explains: “It’s true to say most of our offshore-related products are shipped in the 25t to 50t capacity range, but we have supplied equipment down to 10kg and up to 1,000t. The marketplace is diverse and to supply it efficiently with unprecedentedly short lead times takes a dynamic manufacturing operation and a team of engineers that understand the challenges it faces.”

Ayling points to Singapore, Bergen, Houston and, closer to the company’s UK headquarters, Aberdeen, as particular hotbeds. Straightpoint’s global hubs and 80 strategically positioned distributors serve these markets and others. Across the board, the wireless capability—Straightpoint products offer a 700m range—of modern load cells is a driving factor in this supersafe environment. Ayling says: “Cabled products were the standard solution until almost seven years ago, and we are still on a curve towards a time where wireless load cells, for example, will be ubiquitous offshore. There is still a need on occasions, if a critical application needs to be permanently powered, for cabled ATEX and IECEx products, but wires need to be heavy, thick and durable to prevent cutting or other breakages. In most cases, removing the cable from a belowthe- hook or other application enhances safety and efficiency many times over.” Straightpoint executes ongoing research and development, which has recently focused on what Ayling calls “black box-style” technology. He explains: “The concept is similar to that used in the aviation sector. The idea is that a marine or offshore company has a black box at their location that stores information over a period of months and the customer can collate or analyse the data.”

A number of recent applications showcase the Straightpoint range. For example, Anchor Industries used water bags in addition to a variety of force measurement and rigging equipment to complete load tests on a 500t Liebherr crane aboard the Van Oord’s pipe-laying vessel, DLB Stingray vessel in Cape Town Harbour, South Africa recently. The main focus for Stingray is S-lay pipe-lay work; when performing S-lay pipeline installation, joints of pipe are welded into a pipe string aboard the vessel. Anchor accepted the job from Dormac Marine & Engineering to complete an overload test of the crane, constituting a 550t load being applied to the main hoist.

Four 75t-capacity Radiolink Plus wireless load cells and four 30t capacity wireless low headroom links, all manufactured by Straightpoint and sourced from Anchor stock, provided data to handheld devices throughout the project.

Tyrone Tilley, national services manager at Anchor, said: “With a test there is always a certain level of stress and to have the Straightpoint products involved gave the team added assurances that the equipment was going to deliver in a pressurised environment. The 120t load cells were from old stock; we are in the process of phasing out those units and replacing them with Straightpoint equipment.”

For the main overload test, a dozen water bags were used in a near-40m, threetier cascading rig. At the top and middle were two 100t and two 40t bags, while three 20t and a 30t bag combined at the bottom. Supporting rigging equipment was allocated to each lifting point; for example, Point 2 for two 40t bags in Tier 1 included a 100t x 7m round sling, two 55t safety bow shackles, above and below the 75t load cell, followed by the water bag.

Tilley said: “The additional capacity in the water bags was to account for water displacement owing to the fact that they were pushing against each other. Of the 650t capacity we had I estimate that we lost approximately 50t to 70t.

“We used handheld devices for this project but have recently acquired Straighpoint’s multi-load cell reading software [SW-MWLC] and look forward to applying it on future applications of this nature.”

Another job involved the installation of cable tensioners aboard the vessel Fugro Symphony. Industrial force measurement specialist Northern Balance employed a Straightpoint 25t Radiolink Plus load cell on board to calibrate these new cable tensioners.

Four huge load cells are fixed on each machine but the Straightpoint unit and digital handheld display were used as calibration tools while the boat was docked in Blyth, Northumberland, UK.

Hayden Rouse, managing director, Northern Balance, says: “The ability to monitor the load cell at a safe distance was a major advantage. With the massive forces involved, the potential for something snapping and causing injury is always present and we always have to be mindful of the inherent hazards associated with such work.”

Rouse provided weighing expertise alongside a team of fitters and welders in addition to a marine architect and draftsman. Only when the alignment mechanism was welded in place could the Radiolink plus and other equipment be rigged. Slings, shackles and the on board crane combined to generate the pulling force. Fugro Symphony is equipped with a MacGregor Hydramarine ‘Active Boost’ 150t AHC knuckle boom crane, capable of subsea lifts of 150t in single fall mode, down to 3,000m. Rouse added: “The 25t Radiolink plus load cell met our capacity requirements and I know Straightpoint equipment to be rugged and reliable. This is the first job we have done for this particular customer but hopefully its success will lead to more work and we wouldn’t hesitate to utilise the benefits of the same technology again.”

HARNESSING THE WIND

Joerg Birkenstock, Demag product manager for wind solutions explains that under the Demag brand the company provides tailormade solutions for manufacturers of wind turbines in order to support the service technicians with fast and safe equipment. “We provide rope winches and chain hoists to lift tools and spare parts up to the nacelle in addition to offering transport solutions with modular cranes inside the nacelle to deliver the parts to the right position in a safe and easy way,” Birkenstock says.

With its Demag DC-Wind chain hoist and DS10-Wind rope winch, Demag supplies lifting solutions that are specially designed to meet the needs of wind turbine manufacturers and operators. The DCWind chain hoist is available in five sizes for load capacities up to 1,500kg and with hook paths up to 180m. It ensures safe and reliable load handling thanks to a brake/ coupling system and corrosion-protected brake and is one of the most frequently used hoists in this industry.

To serve offshore applications, Demag has developed a logistics system to be used inside the nacelle, which can be deployed under harsh conditions at sea, and it significantly cuts lifting times. The modular system is based on the proven concept of the Demag KBK light crane system and the DS10-Wind rope winch.

The rope winch is supplied in four sizes and installed in the nacelle of the wind turbine together with the KBK installation. It has a maximum hook path of 180m and can lift spare parts, equipment and tools weighing up to 1,000kg at load-dependent lifting speeds of up to 48 m/min. The system can cut the time for lifting operations to a third, the company says. Thanks to the customerspecific configuration of the KBK modular crane system, any point of the nacelle can be served with Demag lifting equipment. “We see a growth in the turbine size, 8, 10 and more MW with higher load capacities that need to be handled,” says Birkenstock. “Our customers are the big players of wind industry who trust in Demag lifting equipment. Therefore our hoists and cranes are integrated in onshore and offshore wind power fields all over the world.”

MacGregor serves the offshore and marine industries by offering engineering solutions and services with a portfolio of MacGregor, Hatlapa, Porsgrunn, Pusnes and Triplex brands.

The company’s three-axis motion compensation crane is designed for offshore rig and wind turbine supply and maintenance operations. The motion compensation system of the crane’s base, combined with active heave-compensation and constant winch tensioning, ensure unmatched lift precision and safety.

Torbjörn Rokstad, director of Mooring Systems at MacGregor, says: “Turbine platforms are about 20m above the water and they are often only a few square metres, so precise load- and personnel handling is necessary. Although MacGregor’s standard active heave compensation (AHC), supplied through a crane’s winch, compensates for the vessel movements, a greater degree of precision is sometimes needed.”

MacGregor has introduced the 3D Motion Compensator (3DMC), a flexible retrofit device that can be fitted to the knuckle jib of a broad spectrum of new and existing MacGregor subsea and offshore cranes.

MacGregor is involved in the world’s first floating offshore wind farms project; Statoil’s Hywind pilot park in Scotland. MacGregor has delivered a Pusnes substructure mooring connection system for each of the pilot project’s five floating wind turbines. “The project hinges on applying proven technology in new applications,” says Rokstad. “MacGregor was chosen for the task because of its long history of designing and delivering very reliable mooring solutions for offshore floating production units operating in harsh North Sea conditions.

“Turbine platforms are about 20m above the water and they are often only a few square metres, so precise load and personnel handling is necessary. Although MacGregor’s standard active heave compensation (AHC), supplied through a crane’s winch, compensates for the vessel movements; a greater degree of precision is sometimes needed.”

MacGregor has announced that it is now building one of the most advanced fibrerope cranes on the market. The MacGregor FibreTrac crane will have a 150t safe working load capacity and will be ready for testing during the first quarter of 2018.

“MacGregor introduced its fibre-rope crane range in 2016. The greatest advantage of fibre rope when handling loads in ultra-deepwater is that it weighs virtually nothing in water,” says Høye Høyesen, vice president, advanced offshore solutions at MacGregor. “This neutral buoyancy means that, regardless of the length of rope paid out, the fibre rope does not add anything to the load experienced by the crane. Cranes can therefore retain their full payload lifting capacity all the way down to a maximum depth. This is in complete contrast to using wire rope, where the everincreasing weight of wire paid out limits the load permissible in relation to depth.”

Modulift UK business development manager John Baker says that they have recently supplied two 1,500t modular beams to Gaylin in Singapore for Tiong Woon, which are ranked at number 18 in the world of crane owning and rental companies.

“The spreaders were delivered to their yard in Singapore Friday last week, and from there they will mobilise along with cranes and a lot of other rigging equipment to the Rapid Project in Malaysia, and the lift is scheduled to take place this month (October),” Baker says. “We have also supplied two 1,500t modular beams to a rigging hire company in the Netherlands. We have seen a huge increase in enquiries for modular beams 400t and above this year and have recently sold 600t beams to lifting hire companies in the UK for general Heavy Lift Hire, we have also seen an increase in large 500t plus bespoke lifting arrangements from UK and Europe, mainly facilitating offshore renewable operations.”

UK based First Subsea is a supplier and developer of ball and taper Ballgrab connectors. The heavy lift tool is designed for high load lifting applications both on the surface and subsea. The connector works on the basic principle of a ball engaged within a taper. As the male connector’s balls roll up the tapers, the strength of the grip increased in direct proportion to the load applied. On location, the connector tool is aligned into position and lowered into a tubular receptacle attached to the equipment being lifted.

“Once engaged it cannot be released until the load is removed. The connector’s self-activating mechanism allows for rapid deployment,” says Greg Campbell-Smith, sales director at First Subsea. Recently, the Ballgrab tool has been used to position offshore wind farm pile templates.

SLING CALCULATIONS

Rope manufacturer Lankhorst produces fibre slings designed for engineered lifts. The Lankhorst Heavy Lift development program is designed to improve knowledge on sling behaviour under different and realistic load scenarios allowing better characterisation of sling capacity.

The testing program aims to simulate realistic load conditions during all offshore lifting phases. The more complex lifting scenario, ship to seabed and reverse, was used to provide a better understanding of the operation, encompassing: lift in air; splash zone; and underwater lift. It is while passing through the splash zone that the lifting slings experience the greatest efforts, says the company. In this phase, the lifting arrangement experiences oscillating stochastic forces as a result of buoyancy effects, sea waves and wind interaction.

Rui Pedro Faria, project managaer at Lankhorst Ropes, says: “We have chosen to look at the complete lifting system, recognising that the slings are part of a complex system where interfaces between the sling, sling arrangement, crane, hook block, spreader bar, other connecting hwardware and lifted mass need to be understood and managed.”

EnerMech provides cranes and lifting services to the oil and gas, utilities and infrastructure sectors.
Four 75t capacity Radiolink Plus wireless load cells and four 30t capacity wireless low headroom links.
Demag DC-Wind chain hoist supporting Service technician for onshore wind installation.
The MacGregor FibreTrac crane will have a 150t safe working load capacity and will be ready for testing during the first quarter of 2018.
First Subsea heavy lift connector below the hook lifting a pile template.
Lankhorst heavy lift sling testing.
Enerpac Synchoist mounted in a frame for positioning gravity bases for offshore wind turbines.