ROPOS ("Remotely Operated Platform for Ocean Science") is an ROV used primarily for scientific research. It was originally build in Vancouver by International Submarine Engineering [1] and purchased by the Canadian federal government. This government program also operated the Pisces IV manned submersible. Pisces IV is now in Hawaii being run by HURL [2] (they found the long-lost two-man Japanese sub which heralded the attack on Pearl Harbor). The funding for the Canadian submersible program eventually dried up but by that time the user group had been established and long term experiments put in place on the sea floor. The Canadian Scientific Submersible Facility (CSSF) was formed and leased ROPOS from the government for several years before finally purchasing the ROV a few years ago. In 2005 the vehicle was extensively rebuilt and now boasts a 4,000-pound (1,800 kg) thru-frame lift capability.
This is a unique feature for ROPOS. It is possible to lift 4,000 pounds (1,800 kg) off the sea floor though this ROV. The ROV does not actually lift the weight but the load is attached to the ROV. The load is lifted by the mid-depth system LARS (launch and recovery system—an enhanced crane modified to accommodate the ROV).
The ROV is controlled and powered from a surface vessel. Electrical power is supplied through an umbilical or tether, which also has an optical fibre for telemetry and data. The technology for this cable is actually quite impressive all by itself. In the vehicle the electrical power is used to power components such as lights and cameras but most of the energy is used in an electric motor to drive a hydraulic pump. The hydraulic pump in turn powers the thrusters and hydraulic components of the ROV. This is referred to as an electro-hydraulic system. Most ROVs work in this way but some are purely electrical, using another interesting invention—electric thrusters.
ROPOS is unusual in a few other ways as well.