Technical analysis: Williams' skate fins

Of the many smaller developments seen already in Spain, Williams have again surprised with a lateral take on the new bodywork regulations by appearing with two vertical fins either side of the cockpit.

The team also appeared with revised sidepods, now taking a more streamlined shape, a BMW-like cooling duct near the cockpit and further revisions to their complex diffuser.

Mounted either side of the cockpit opening, the two parabolic fins rise up vertically to the maximum permissible height. These fins act like the "Viking horns" seen on last year's McLaren and BMW Sauber, by altering the flow to the rear wing. Bodywork the size and position of Viking horns are banned in the new rules.

Despite the new regulations aiming to rid the cars of extraneous bodywork, the rules are only worded to create boxed zones around the car where bodywork can and can't be added. Additionally, the sidepods are broken up into three volumes with only simple curvature and a minimum radius of 75mm allowed.

However, these three volumes do not apply to bodywork towards the car's centre line. For the area in which Williams have added these fins, the rules need to create a 75cm space for the cockpit's side padding and thus bodywork inside this area is exempt.

Equally, a narrower 25cm area either side of the roll structure is open to additional bodywork.

While these fins are quite legal within the bodywork rules, the FIA often takes a negative stance to bodywork sited around the cockpit opening on safety grounds. This may require clarification from the FIA when the teams arrive in Melbourne for scrutineering.