First drillship: comparing the derrick to a Boeing 747-400

What a difference a few weeks and indeed months makes when you are having a Drillship Built.

The most noticeable events since last time are a combination of the Hull, which now resembles a ship that most can see as nearly completed, and also a derrick that in the last few weeks came on leaps and bounds which is now installed on the vessel.

Weather played an important factor in some date changes for this milestone event however on Sunday 3rd March 2013 we were pleased to see the derrick in place after it had already been transferred from the build site and had been standing on the quayside in Samsung shipyard for the opportunity to have a weather window that suited for the big lift. ( 1748.00 Metric tons )


If we take the derrick and all its various equipment then it may be better to put it all into a bit of perspective which will also become apparent when you look through the pictures.

Overall height of the derrick is close to 66 Meters (215 feet.) Which if you also consider that the drill floor structure which is approximately 37 meters (121 feet) from the bottom of the hull. Overall from the bottom of the drillship hull to the top of the derrick is close to 103 meters (337 feet.)Compare those dimensions with a Boeing-747-400 jet, which has a length of 56.31 meters (184.9 feet) or a wingspan of 59.64 meters (195 feet) and you get a scale of the derrick structure alone.

If we look at the comparison of weight of the derrick versus the weight of a Boeing 747-400, then that also puts some perspective on the derrick structure, which when all equipment is installed which was the case when the Crane barge lifted it onboard the derrick weighed in at 1748.00 Metric tons. In comparison a fully laden 747-400 which weighs in at approx 408 Metric Tons.

That’s nearly 4.3 fully laden Boeing 747-400’s, for the weight of a single derrick on these vessels.

Now if we consider the crane barges you see in the pictures of the derrick installation. The smaller crane barge which transported the derrick from the build yard to beside the vessel had a capacity of 3600 Tons, whereas the crane barge that lifted the derrick onboard has a lift capacity of 8000 Tons.

Comparison of Maersk Advanced Drillship versus one of the first drill ships used.

This is an interesting item when we compare one of the first drillship which was known as the CUSS 1, which is believed to have had dimensions as follows which was taken from the Internet.

Length 260 feet x 48 feet with a draft of 10.5 feet. Having a Gross Tonnage of 3000 tons.

This vessel was a surplus navy barge, on which they positioned a full-size rotary drilling rig directly over a hole built through the vessel’s hull (Somebody quickly nicknamed it the “moon pool,” which it’s still called today). This diamond-shaped aperture allowed the drilling and hoisting equipment to be installed over the barge’s midline, rather than over the side, for much improved stability while drilling. Aptly, the unit was christened the CUSS I, and according to the book, it contained some distinctive equipment.


“Two other unique features went into the CUSS 1 design. Special vertical guides welded inside the derrick served as rails along which the frame of the rig’s six-ton traveling block moved. The frame contained sheaves for the wire rope that moved up and down from the drawworks during drilling. The vertical guides kept the traveling block from swaying dangerously in response to vessel motion. In fact, from that point on, builders fitted rails for all traveling blocks on the derricks of floating MODUs. Also, engineers installed a mechanical pipe-handling system that stacked stands of tubulars (casing, drill pipe, and weighted drill collars) horizontally on deck and could raise them quickly to the vertical position in the derrick for lowering into the hole. This system achieved two things. First, it eliminated the need to rack tubulars in the derrick, a common practice on land rigs and bottom-supported MODUs, but obviously unsafe aboard a floating rig. Second, it all but eliminated the sometimes-dangerous job of derrick man. Maintenance and other non-drilling duties, however, at times still required men to work high in the derrick.”

Maersk drillships dimensions:

Length, 228 meters (748 feet)

Width overall: 42 meters (138 feet)

Water depth for operating: 3,600 meters (12000 feet)

Drilling Depth 12000 meters (40000 feet)

This hopefully shows the advancements that have been made with our vessels and indeed the view from many that as well as setting the standards with automation and safer working environments, we (Maersk Drilling) have moved forward in leaps and bounds, from the early vessels, and also some of the standard current vessels of competitors.

Notable events in Korea site team over the last few weeks.

On the evening of 28th Feb, Alex Macdonald Senior Toolpusher, celebrated his 25 years anniversary with Maersk Drilling.

In the company of all members and family from the site team, and some very entertaining evening discussions, a fantastic night was had, with good food and entertainment.

Erik Juul Madsen, presented Alex with gifts and good wishes from all and with much joy Alex also had well-wishers congratulating him via video feed from fellow employees who remembered Alex from years past.

He’s looking forward to the next milestone anniversary.

Enjoy the pictures and stay tuned.


Check out more blog posts