Operation Glimmer - Glimmer and Taxable

Glimmer and Taxable

Glimmer and Taxable were very similar operations. They were executed in the early hours of 6 June 1944, whilst the invasion fleet was approaching Normandy. Taxable simulated an invasion force approaching Cap d'Antifer whilst Glimmer threatened Pas de Calais. By dropping chaff in progressive patterns, Royal Air Force bombers were able to create the illusion of a large fleet on coastal radar screens. Beneath the chaff small boats towed radar reflector balloons and simulated the radio traffic expected of the larger force. If successful in drawing German forces toward the coast, RAF bombing raids would target bridges and roads to keep the armies away from Normandy.

The operations required precise accurate flying, in elongated circuits, with replacement aircraft having to merge in seamlessly to avoid tell tale gaps. The bombers were staged at 2-mile (3.2 km) intervals parallel to the French coast; they would spend two and a half minutes flying toward the coast, dropping chaff at 15 second intervals, before turning and heading away from the coast for two minutes and ten seconds. By repeating this circuit the wide cloud of chaff edged toward the coast just like a real sea-borne fleet. The aircraft had to be modified by cutting a hole in the nose to allow the large quantities of chaff to be dropped.

Taxable, the larger of the two operations, was carried out by 18 small boats, a mix of Harbour Defence Motor Launches (HDML) and Search and Rescue Pinnaces, designated Special Task Force A. Chaff was dropped by Lancaster bombers from the famous No. 617 "Dam Busters" Squadron, with each aircraft carrying an expanded crew of up to 14. The squadron began training for the operation as early as 7 May, but were not aware of the final target or intention.

Task Force A left port in the evening of 5 June but struggled in bad seas, which affected their equipment and ability to converge at their meeting point. However by 00:37 on 6 June, the lead boats were on schedule and had reached the muster point and were headed toward the French coast. Between 02:00 and 04:00 the ships operated radar and radio equipment as they headed toward a point 7 miles (11 km) offshore. From there the task force simulated a landing attempt, by running fast to within 2 miles (3.2 km) of the beach, before returning to the 7-mile marker under cover of smoke. During this time only a small German response was observed – searchlights and intermittent gunfire. Shortly after 05:00 the operation ended, and the task force laid mines before heading toward Newhaven, reaching it by mid day.

The air operations for Glimmer were conducted by No. 218 "Gold Coast" Squadron under Wing Commander R. M. Fenwick-Wilson. The squadron, which flew Short Stirling bombers, was much smaller than No. 617 and so no relief aircraft were available. Instead, each aircraft carried two pilots who rotated flying duties. The naval contingent, Special Task Force B, consisted of 12 HDMLs commanded by Lieutenant Commander W. M. Rankin. Also equipped with jamming gear, radios and balloon, they began jamming operations at shortly after 01:00 followed by radio chatter around an hour later.

Glimmer elicited more response from German forces than Taxable, including reconnaissance planes sent to investigate the "fleet". After completing their assignment (which, unlike Taxable, did not include laying mines) the ships returned to port, reaching their berths by 13:00 on D-Day.