Below is a representation of the work done by Sid Nanson who, at his own expense, obtained whatever records were available, and carefully and diligently assembled into this list. If you any additional information, please contact John at HMRM461@aol.com.

Four prototypes (BuNo 133732/133735) were built and were powered by a pair of 1900 hp R-2800-54 engines housed in lateral nacelles.

The production model included modified engine nacelles, twin main landing gear and a dorsal fin. A total of 55 were built for the USMC (BuNos 138418/138424, 140314/140325, 141603/141617, 145855/145875). They were redesignated CH-37C in 1962, and 36 were cancelled (Bu147101/147136).

Piloting 140316, Maj. R. Decker Anderson set a World Speed Record of 162.7MPH on November 11, 1956 at Windsor Locks, Connecticut. The HR2S held that record up to May 17, 1961. On November 9, 1956, he set an Altitude with a 5,000-Kilogram Load record on November 9, 1956, of 12,100 feet. That record was held until April 16, 1959.

A Greatest Load Carried to an Altitude of 2000 meters of 6,000 Kilograms was set at Stratford, Connecticut on November 10, 1956. That record was held until to October 30, 1957. The first four aircraft received by HMR(M) -461 did not have tail numbers. They were simply marked A, B, C and D. 140316 went through a pilot overhaul late in 1957 in Jacksonville, FL, and set up the standard for HR2S overhauls.

The Navy had 2 of the Airborne Early Warning version, with the AN/APS-20E radar scanner in a large nose radome, built (BuNo 141646/141647).

145872 (N7393, C/n. 56-114) has been allocated to the International Helicopter Museum in Weston-super-Mare, UK. It was delivered to the US Marine Corps HMR(M)-463 at MCAS El Toro, California, in 1959. It was later transferred to Headquarters & Maintenance Squadron 26 at MCAS New River, North Carolina, with whom it stayed until August 1966.

The aircraft was then withdrawn from service and transferred to the Military Aircraft Storage and Disposition Center at Davis Monthan Air Force Base. The aircraft remains stored in the United States awaiting a suitable opportunity to transport it to the UK. With an empty weight of approximately 9500 kg (20943 lb), a fuselage length of 19.58 m (64 ft 3 in) and a width of 8.20 m (27 ft) this is likely to prove impossible without sponsorship.

SOC - Struck Off Charge
GTA - Ground Training Aid
W/O - Written Off