The eISR brings an exciting challenge to the sport of human-powered submarine racing. Where other races have focused on straight-line speed, the eISR introduces a slalom course. The emphasis is still on speed, but the subs score faults for all interactions with the course markers - the sub which finishes with least faults and fastest time wins!
Retaining the one-boat-at-a-time, race-against-the-clock format of other human-powered submarine races, the eISR is an out-and-back race, with a set of slalom gates on the return leg. The figure below shows the layout of the racecourse. A timing gate is set up on the outbound leg, 13m long, 42m into the leg, so that speed records are reasonably compatible with those set in other races. Shortly after the timing gate, the submarines will have to make a sweeping 180° turn, on an approximately 25m radius. A set of four slalom poles are placed on the return leg. Subs have to leave the first and third poles to starboard, and the second and fourth to port. The poles are placed 13m apart. On the first race day, the poles are placed wide, so that subs can run a straight line through them. As the week progresses, they are moved closer to a straight line, forcing tighter turns. The slalom section is deliberately placed on the return leg to slow the boats down before they reach the finishing area. Any sub which touches the end net will score faults. The total length of the race course is approximately 175m, but the distances travelled by the subs may be longer or shorter, depending on how tightly they take the sweeping turn and slalom gates.
Course marking and faults
The Ocean Basin is essentially a very large, very well lit, swimming pool. The bottom is made of rectangular light-coloured concrete slabs joined by lines of black tar. The water is clean and clear, with horizontal visibility typically of about 30m. There are a lot of reinforcement structures along the bottom and around the edges of the pool, so pilots and support divers will have to take care when operating near these structures.
The centre line of the course is marked out along the bottom using a weighted line and a set of small coloured cones. The outer edge of the curve is marked on the bottom with a string of larger traffic cones.
The starting line will be 30m from the end wall of the basin, and is marked by a pair of PVC poles placed on a tar line across the bottom of the tank. Additional traffic cones placed along the tar line signal to the focussed pilot to stop pedalling!
Timing gates are placed at 42m and 55m from the starting line. The gates are vertical PVC pipes anchored on the floor, placed on either side of the course. The gates are solid enough to survive impact, but will give way to minimise damage during such an event. They are designed to be quickly replaced and recalibrated after a collision.
Two turning gates, consisting of a pair of vertical PVC pipes, are placed to mark the sweeping turn. Subs are required to leave a black & yellow pole (green in the diagram) to port, and a grey one (red in diagram) to starboard.
Slalom poles consist of vertical ropes covered in swimming pool "noodles". Subs leave red striped poles to port, and yellow striped ones to starboard. The poles will initially be placed such that the subs can steer a near straight-line through them. As the week progresses, the poles will be placed such that the subs will have to weave between them.
The finish line is marked with a pair of PVC poles and a brightly coloured tape across the floor. Pilots must stop pedalling, and engage their sub's braking system (if fitted) as soon as the bow of the submarine crosses the line. A submarine-catching safety net is placed across the arrival zone, 30m from the finish line, but eight faults will be applied to any submarine which makes contact with the net.
The gate, marker and slalom poles are anchored with lead weights placed on 18" steel disks. Any contact with any pole will result in four faults. If the anchor is dragged off the plate, then eight faults will be applied. If a sub misses a gate altogether or by-passes a slalom pole, eight faults will be assigned.
Submarines must remain submerged while on the course between the starting and finishing lines. Every instance of any part of the submarine breaking the surface will result in four faults being awarded.
The Races run over ten days. The first day (Wednesday) is a dry day of final readying and dry judging. Once teams clear the dry checks, they and their submarine are allowed into the Ocean Basin water, where the next two days are dedicated to diver checkouts, ballasting and wet safety checks. The weekend is an opportunity to revisit elements of the design which didn't do well in the initial testing or to modify the design to satisfy the judges' requirements. The races proper start on the following Monday and run through to the end of Thursday. The Friday Agility Competition is a separate event which teams must qualify for over the course of the week.
The race is run in heats, one in the morning, and one in the afternoon. Six boats can take part in each heat, as decided by drawing straws the night before. The Order of Racing is also determined the night before, and is followed as strictly as possible during the course of racing operations. Exceptionally, the Queue Manager can use his authority to vary the order. Timing on the day depends on many circumstances, but the aim is to launch the boats beginning at 0800, and start racing at 0900. The morning heat runs until noon. A one-hour break at lunch allows the staff a break and a reset of the course as required. Any remaining boats are launched beginning at 1300 and the afternoon heat starts an hour later at 1400. Racing typically ends for the day at 1700. The goal is to be clear of the QinetiQ site by 1800.
Subs are readied in a set of three boxes (Ready, Set and Start) marked out on the basin floor behind the starting line. The Queue Manager (“Q”) controls the order of submarines into the Ready Box, notifying the Dive Controller accordingly. The Dive Controller coordinates the movement of teams through the boxes using an underwater loudhailer. When a sub has reached the starting box, the crew have completed their final checks, and the pilot is ready to start, they indicate their readiness to race to the Dive Controller, who confirms the racecourse is clear, and gives them the clear to start signal. The clock starts when the bow of the submarine crosses the starting line. Boats proceed through the timing gate, around the turn, through the slalom section, and over the finish line. The finishing time is when the bow reaches the finish line. The pilot then exits the submarine, and is brought to the surface by one member of the team. The other team members return the boat to the end of the current queue, and prepare it for another run.
Aborts and safety
While on the racecourse, the submarine is followed by two inflatable boats at the surface, one carrying a team of rescue divers and the other a submarine recovery team. A pilot may indicate a non-emergency abort by releasing the safety buoy, opening his hatch, and swimming to the surface, where he or she is recovered by the rescue boat. The tow boat then recovers the buoy and hauls the submarine to the surface, finally towing it back to the starting area. If the submarine indicates an emergency abort (the safety buoy is released, but the hatch does not immediately open), or it is obvious that it is in difficulty, the rescue divers immediately dive to the machine, extract the pilot and bring him/her to the surface. The submarine is then removed from the racecourse by the tow boat. Once the stricken sub is clear of the racecourse, the rescue divers return to the surface and inform the Race Controller, so that racing can resume.
Repairs and modifications
An important part of the Races is the on-the-fly repair, modification and improvement of the submarines during the course of the week. In the 2016 competition, new pre-qualification requirements were introduced to ensure that all boats were ready to go on the first day of racing, but this is submarine racing. Stuff goes wrong. Other teams do it better. Teams learn from experience operating their boats on the racecourse and look to incorporate improvements and modifications in their drive for the top of the podium.
Each team will be provided with a working space (dry pit) around the edges of the Ocean Basin, where they can do minor adjustments, and any work not requiring the creation of dust. Any dust-making activities will have to take place outside the building. All power tools will have to be appropriately tested, and personnel using them will need to demonstrate that they are suitably trained and experienced.
Awards are given for speed and agility. The top prize combines the two, and includes a significant element of design and manufacture, to encourage creativity and innovation.
- Grand Prize – eISR Trophy and All Round Runner Up
- The overall winner of the eISR trophy is determined by a formula combining design, manufacture, race performance and reliability.
- Week's Top Speed
- This prize is awarded for the fastest transit of the timing gates during the week. The sub must complete the run for the speed to stand.
- Agility Award
- On the last day of the competition, qualifying teams run a double-length course, twice through the timing gates and slalom course in an agility challenge. Teams have to qualify to compete during the course of the week: only those teams with a suitably high Completion Ratio are allowed to compete.
- Award for Innovation
- This prize is presented to the team which, in the judges´ combined opinion, has pushed the engineering envelope the furthest. By its very nature, innovation is hard to categorise, but the eISR´s experienced panel of submarine engineers know to recognise it when they see it!
- Best Presentation
- This award goes to the team which best presents its submarine design visually and verbally to the judges and other teams during the course of the week.