by Jay Sloane

  In the notes about different types of windscreens used on the Lotus Eleven (Dark Ages item # 15) mention is made of the single-seat cockpit configuration most often associated with the car.  This single-seat cockpit is sometimes referred to as the “LeMans” body configuration, usually a part of the LeMans package with disc brakes and deDion rear suspension.  It is one of the most striking features of the Eleven and proved to be very effective in any competition event in which it was permitted.  This was part of the Eleven’s super-aerodynamic bodywork, drawn by Frank Costin, engineer for DeHavilland Aircraft and brother of Mike Costin, the unsung hero of Lotus.

  When Frank Costin began to adapt his aviation-inspired concepts to Lotus racing car shapes, he took great pains to impart directional stability into his designs.  At the time racing cars were of course faster than road cars but not necessarily better handling, with slippery tires and high drift angles the norm.  Safer control of the car at high speeds became an obsession to him, at least as important as creating a low-drag shape.  The pronounced tail fins on the Mark 8 & 9, for example, had nothing to do with styling.  Costin simply felt that aerodynamic improvements to allow the car to travel faster should also bring aerodynamic resistance to sidewinds, and help the driver keep the car going where it was steered.  

  By late 1955 when the Eleven was being designed Costin again incorporated a vertical stabilizer into the shape, although drag reduction was now the main function. ¹  This time the side fins had been reduced to mere trailing edges of the wheel enclosures.  But there in the headrest was a tailfin more obvious than ever.  In keeping with the modular, street or race, nature of the Eleven this “fin” could be removed.  So when the “Press Car” was unveiled in February 1956, body panels were laid out on the ground.  Potential buyers couldn't miss:  this car could be driven with either the racy single-seat cockpit with its dashing  headfairing, or as an almost practical open two-seater with a low-profile “boot.”  The new rocketship for the road set many a young man’s imagination afire.

  In Dennis Ortenburger’s book on Costin, the single-seat bodywork is called “ yet another pure aerodynamic shape to cover the driver. (Costin) arrived at an elongated canopy and then sliced its top off half way back to allow the driver to get in.  What remained in front of him and to the sides was perspex.  The aft section was formed in aluminum and although called a headfairing it really wasn’t.  In Costin’s scheme the entire shape, windscreen and headrest, faired the driver and tests showed that the air flow remained remarkably well attached even above the actual opening.” ² That pure shape is best illustrated with the “Monza” bodywork as seen here.

  Not every full-spec “LeMans” Eleven had the single-seat cockpit, and some Elevens that did were not LeMans.  Many Elevens were delivered to their owners with full sets of road and track screens and corresponding bodywork. The factory called the single-seat addition a TOP KIT  and it was an option with the purchase of any Eleven or body chassis unit. There was a proviso of course: the center section and passenger's door had to have a recess for the tonneau which would have been hard to add afterwards -- plus the easy addition of Dzus fastener clips. The aluminum headrest was only attached to the tail section with Dzus fasteners, and so could be used as needed.  Whenever the single-seat windscreen was removed in favor of a full-width ‘screen, the headrest was usually removed too because it immediately became an air brake without the forward half of Costin’s “canopy.”  

  Ironically, the single seat cockpit with headrest were never used on the Elevens that raced at LeMans.  In that race a full width windscreen was required from 1956-on for cars that were ostensibly “two-seaters.” The same was true in 1957 for Sebring and wherever the Eleven raced under the rules of FIA appendix C.   Due to this regulations change, a higher percentage of Series-2 Elevens were delivered with the full width screen, and no headrest.

  In American racing the single-seat configuration with headrest was far more popular with buyers.  Only the SCCA requirement of a rollover bar caused a problem.  On the Eleven the easiest place to mount a rollbar was the rear face of the seatback, with a reinforcement tube from the bar back to the right-rear corner of the chassis.  This arrangement could be made to fit unseen under the headrest, but aluminum had to be cut to make it work.  To open and close the tail section the headrest would first have to be removed, revealing slots and holes in the upper bodywork to clear the tubes.  The example at left is typical.  A few clever owners also modified the headrest so that the front face was removable, to enable it to the clear the bar.

  The factory solution may have been at the request of Jay Chamberlain, and only for the American market.  Many years later Chamberlain recalled ³  that as so many buyers wanted the headrest, a request was made of the factory to make it integral with the tail.  This is consistent with the factory announcement:  In view of the recent S.C.C.A. ruling, a crash roll bar will be fitted as standard to the chassis and this is hidden inside the head fairing. In order to supply this, of course, the head fairing must be part of the tail and not removable. ⁴  In this setup the headrest was open into the rear compartment, and so the entire tail could be opened or closed around a rollbar without the need to cut anything.  The integral headfairing is rare enough in the USA, and almost impossible to find elsewhere.  In the photos at left we may have some of the factory examples.  In any event, despite the existance of a few integral headfairings, most Elevens continued to be produced with the removable type.  

This is a good place to insert a photo of the factory rollbar and photos are all we have of these today, as original examples were replaced as more stringent standards went into effect.   Note that the rollbar on this early chassis is slanted back to allow clearance for the hinged tail section, actually making it less effective in protecting the driver.  The priority was clear.  But Lotus may have made a change to the frame design to better support the rollbar later (mid-1956) by switching the seatback diagonal tube to the driver's side.  This is speculation but it makes sense. 

 A few homemade headrests found their way onto Elevens too, such as the one on Dave Tallaksen's ex-Sebring car.  The sketch at lower left is one eyewitness' recollection of the unique addition to Bob Bucher's Club model, raced in the Northeast USA in the early 60s. (Does anyone have more on the Bucher Eleven? )

Lotus shrank the headfairings on later models, as on the 15, with minimal effect on vertical stabilization and more on simply shaping the airstream around the driver.  Only a few 17s had headfairings, and the mid-engined 19, 23 and 30 had none, relying entirely on the windscreen to shape the airflow.  It had already been observed with the Eleven that stability was good with or without the headfairing.  As for shielding the driver, Lotus had shown with the '57 LeMans Elevens that it could be done with careful shaping of the 'screen and a higher seatback line.  The headfairings on those cars seems less prominent as a result.  Those special cars for LeMans mark the last time Frank Costin was involved with the shape of the Eleven.