OVERVIEW:  The Mk 37 Mod 1 is a heavyweight U.S. Navy submarine-launched anti-submarine torpedo introduced in 1961; it is wire-guided and built on the earlier Mod 0 design.

DETAILS:  “Mark 37” is the U.S. Navy's post-WWII acoustic torpedo series; “Mod 1” denotes the first major upgrade adding wire guidance to the original passive/active system. The Mod 1 variant is 161 in (4.09 m) long 26 in longer than Mod 0 and weighs approximately 1 690 lb (767 kg), an increase of 260 lb. It carries a 330 lb (150 kg) HBX‑3 warhead with a Mk 19 Mod 1 contact exploder. Powered by an electric motor with silver‑zinc batteries, its speed settings mirror Mod 0: 17 kn with ~23 000 yd range, or 26 kn with ~10 000 yd. Guidance begins with gyroscopic stabilization, then wire guidance during mid-course, and finally active/passive homing in terminal phase.

TYPE: Heavyweight submarine-launched wire-guided acoustic homing torpedo

FUNCTION:  After launch from a 19‑in (in‑21‑in guide‑rail) sub tube, gyros maintain the course initially, then the submarine controls the torpedo via a wire during cruise phase, enabling mid-course correction. In terminal approach, the wire releases and the torpedo switches to passive/active sonar to home in and detonate on contact.

NOTE:
IOC: 1961
Manufacturer: Naval Ordnance Station Forest Park (and others), USA
Operators: United States; exported to allied navies under Military Assistance Program (Mod 1) 
Platforms: U.S. Navy fleet and nuclear submarines equipped with 21‑inch tubes

SOURCE: 
A Brief History of U.S. Navy Torpedo Development – Part 2; Mark 37 torpedo (Wikipedia); History of Torpedoes – Parts 1 & 2 (cribbed from Naval archive)