Design

From the outset, the design team at Goodwood were adamant that the Phantom Drophead Coupé should be more than simply a convertible version of the Phantom. “Designing without compromise meant that, to a certain extent, we had to start again,” says Rolls-Royce Chief Designer Ian Cameron. “Simply removing the Phantom’s roof could have made a great convertible but it wouldn’t have made a perfect one. With the Phantom Drophead Coupé we had the chance to think about the very nature of convertible motoring and, in particular, what it means to Rolls-Royce.”

Every exterior panel on the Phantom Drophead Coupé is new, echoing the Phantom’s style but with carefully considered proportions more suited to the shorter body. From the raked front end to the sweeping rear, every aspect was studied at length to ensure that the finished car looked purposeful and elegant both with the hood up and with it stowed. For the interior, the concept was simple: bring the outside in. Create a social space enabling occupants to embrace the elements using sumptuous, relevant materials.

As well as considering the finer details of the package – seating arrangements and dashboard layouts, for example – the designers also developed some fundamental beliefs about how the materials they were using should work. The entire team was keen to keep things as natural as possible and, as a result, there is an instant, raw beauty to the Phantom Drophead Coupé. Materials are used in a way that emphasises their natural charm and there is an immediacy to the exposed elements of brushed steel and solid teak. Bleaches, stains and lacquers were shunned as far as possible in favour of more natural finishes. Hands touch only chrome, leather or wood. Other materials, such as the brushed steel, are used as architectural detailing, giving the whole car a sense of visual tactility.

“The Phantom Drophead Coupé is about emphasising the essentials of pleasure,” says Cameron. “Above all, we were determined to make this car a joy to live with. Rolls-Royce is the opposite of stiff formality. Why would you design and build a car like this and not make it fun to use?”

Craftmanship

Craftsmanship is a hallmark of Rolls-Royce. From the traditional wood and leather workshop skills to the complex welding of the aluminium spaceframe, a 21st century Rolls-Royce is a blend of hand crafted expertise and high-tech materials and techniques.

With more than 350 man-hours invested in each car, not including the time taken to build the engine, nearly right is never acceptable. The maxim of company founder Sir Henry Royce still resonates around Goodwood today: “Strive for perfection in everything you do.” From day-to-day production cars to the often complex Bespoke requests, Rolls-Royce has a skilled team adept at meeting the challenges of crafting the finest cars for the most discerning customers.

For example, a number of the individual leather pieces used in the Phantom Drophead Coupé are larger than those in the Phantom, which makes their selection and usage more difficult because of naturally occurring blemishes and imperfections. The skill comes in using each hide in such a way that these natural marks are hidden or discarded, minimising waste and resulting in a perfect finish.

Other new materials, such as the teak and brushed steel, bring with them their own unique challenges. Wood is a defining feature of the Phantom Drophead Coupé, and the woodshop team can spend up to a month preparing, matching, shaping and finishing each car’s set. The teak deck is finished with a specially formulated oil blend to ensure a rich, natural, longer-lasting lustre. Its use on the Phantom Drophead Coupé is unlike any other in the automotive industry. With the brushed steel, the difficulty lies in getting exactly the same look to each of the parts – the grille, the bonnet and the A-pillar. After a great deal of research and testing, machine-brushing finished by hand-polishing was deemed the best way of achieving a uniform grain.

Craftsmanship can be found throughout the Phantom Drophead Coupé, from the largest, most visible parts down to the smallest, unseen detail. By constructing each car with the same enthusiasm and passion with which it was designed, Rolls-Royce ensures that each one will offer a unique motoring experience, both to its owners and to all those who will travel in it.

Engineering

The challenge in designing any convertible lies in retaining a high degree of torsional rigidity throughout the body while keeping weight down. Torsional rigidity is vital to minimise the scuttle shake associated with most convertible cars and to help maintain the car’s dynamic composure.

Extensive testing and research were carried out before the engineering team were completely satisfied. Tens of thousands of kilometres were driven over rough road surfaces to help identify and eliminate potential problems. The result is a spaceframe chassis that makes the Phantom Drophead Coupé perhaps the most rigid convertible available today. The clearest indicator of this incredible strength and stiffness can be seen in the rear-view mirror, which shows no vibration at all, even at high speed.

A great deal of this is due to the modifications around the triangulated A-pillar. The entire windscreen surround was designed to be an integral part of the roll-over protection system. Consequently the A-pillar struts run right down to the floor of the car. Additional aluminium extrusions have been utilised, along with wider sills. The rear haunches have single extrusion beams running at waist height on either side. In all, more than 140 metres / 460 ft of weld go into each Phantom Drophead Coupé body – 20 metres / 65 ft more than in the Phantom. Incorporated into the rear spaceframe structure is the concealed roll-over protection system which deploys from within the rear head restraints in just a fraction of a second in the event of an accident. A ratchet system then locks them in place.

Further adding to occupant safety, frontal impacts are absorbed by crumple zones directed into Y-shaped chassis members and the main understructure – the strongest part of the chassis. Side impact intrusion is minimised by the double-skinned floor construction, strong side sills and integral side impact bars in each door. Additional braces above and below the engine bay and under the rear axle add further rigidity to the spaceframe.

Other safety systems include intelligent braking and restraint systems, combined with integral seatbelts. As a result, the Phantom Drophead Coupé is perhaps the safest convertible car on the market.

The spaceframe is constructed at the BMW centre for aluminium competence in Dingolfing, Germany. Manufactured to within a tolerance of just 0.1 mm / 0.004 in, each spaceframe is welded entirely by hand. They are then checked by a computer-guided machine to ensure absolute accuracy.

One of the more interesting problems encountered by the engineering team was the proximity of the optional brushed steel bonnet to the aluminium front wings. These materials are not normally used alongside each other due to the adverse corrosion effects of aluminium on steel. An integral part of the testing process was a 20-year-old DeLorean car. Manufactured with stainless steel exterior panels, it provided an interesting case study into the long-term durability of the material.

All of the panels used on the Phantom Drophead Coupé are unique to this car, representing some of the 1300 new parts used. Unlike on the Phantom, the front wings have been constructed from aluminium using the ‘superform’ technique, in which aluminium is heated to the critical temperature before being literally sucked down over a mould to form the large, complex shape.