Gulf Star Marina has been receiving a lot of praise for its revolutionary new marina. The automated storage and retrieval system is truly a technological marvel. Included in this achievement are the critical technological and engineering contributions from IMM Quality Boat Lifts that were necessary for the automated marina to function properly. IMM Quality Boat Lifts brought four major contributions to the project: 1) An industrial duty Superlift, engineered to run all day, every day. 2) Modifications to the Superlift structure to work seamlessly with the automated rail mounted shuttle. 3) Designing a universal bunking system that will accommodate boats with stepped hulls, v-hulls, catamarans, pontoons or tri-toons up to 16,000 pounds and 40 feet in length. 4) Building a one-of-a-kind boat lift control system that communicates with and perfectly integrates into the automated storage and retrieval system. Getting the boat out of the water is an important first step, and without IMM Quality Boat Lift’s expertise, this first-of-its-kind project would never have come to fruition.
Industrial duty 44,000 pound Superlifts were installed in both of the marina slips. Unlike the Superlift, typical boat lift drives (E-drive, Sea-Drive, H2, etc.) use a screw gear to turn a toothed gear. These drives are highly inefficient (~30%) which makes them very difficult to backdrive (the ability of the toothed gear to turn the screw). This allows manufacturers to save money by not including a brake. It is kind of scary that the only thing holding the boat up on those lifts is the inefficiency of their drives. On the other hand, Superlifts use cycloidal drives. These amazing drives are super-efficient (>96%), have no teeth or screw threads to wear out or break off, and use fail-safe brakes to hold the lift in place. The greater efficiency of the Superlift drive translates into faster lift speeds and lower energy use. The bombproof design of the cycloidal drive allows us to offer them with a lifetime warranty.
Many modifications were made to the standard Superlift to make it function with the automated rail mounted shuttle. The key factor is that the lift must come to the exact same “up position” every time so that the rails on the lift perfectly align with the rails on land allowing the automated shuttle to function properly. In the picture below, the rails are aligned properly.
We also wanted to minimize forces that could misalign the cradles. Therefore we used pivoting cable pulley brackets to minimize side-loads from pulling the cradle beams off-center. These pivoting pulleys will also result in greater cable life.
The automated shuttle is connected by an electrical communications cable that provides power and carries the signals that control the shuttle’s movements. We installed a channel down the center of the cradle (see red arrow in the picture below) to capture and support the automated shuttle’s electrical control cable.
We installed roller guides to travel up the sides of the rectangular concrete piles to prevent the lift cradle from shifting from side to side or from front to back within the slip. These guides prevent the lift cradles from shifting with changing currents and when a boat enters the slip.
The slip’s concrete seawall has a concrete support for the land side rails that extends out over the water (see picture below). We used roller guides that traveled up both sides of the concrete support to set the side to side position of the lift’s cradle. We developed an alignment locking mechanism that had a square tube with a bracket and two guide rollers installed on the underside of the concrete support for the land side rail (not visible in picture). This element was installed perpendicular to (90 degrees) a matched square tube with a bracket and two guide rollers (shown below as “Alignment Locking Mechanism”). These two elements come together (think interlocking C’s) and set the three dimensional position of the lift cradle so that the land side and lift cradle rails are perfectly aligned.
To provide walk around access for the marina staff, we installed port, starboard and stern access platforms. The platforms are made from Thru-Flow to provide maintenance-free decking in a marine environment. For added safety, we also installed handrails along the sides of each lift.
One of the biggest challenges was designing a universal bunking system that would accommodate any boat up to 16,000 pounds, 12 foot beam and 40 feet in length. There are so many different shapes and sizes of boat hulls that our engineers had to design a highly flexible system for the lift. We started with adjustable bunk brackets that can rotate (see below). These brackets allow the bunks to be vertical or angled and they provide the flexibility to deal with different beam sizes.
Another key element of the universal bunk system was the bunk covers. We used a cushioned PVC bunk cap. These covers have just the right amount of give that allows the bunks to better conform to a variety of hull shapes including standard or stepped hulls. Another neat feature of the universal brackets is that they can fold down out of the way (see below). This allows the installation of specialized bunks for catamarans, pontoons and tri-toons onto the lift cradle.
The final, and possibly most impressive engineering contribution, was the one-of-its-kind control system (see below). Common power came in for both Superlifts and split to the two shut off switches. Each lift had its own control system which allowed each slip to operate independently and simultaneously. For safety, each control system had a ground fault circuit interrupter with a fault indicator light to alert the staff.
The marina’s automated stacker system is powered by 480-volt electrical service and the electrician delivered 480-volt power to the Superlift site. Boat lifts typically utilize only 240-volt power, so we had to find components and design a control system that could handle this high voltage. Here you can see the power supply, terminal strips, relays, variable frequency motor drive controllers, brake contractors, and logic module (see below). These controls incorporated a soft start and soft stop to decrease the shock load (mechanical stress) which will extend the life of the lift. These controls also directly communicate with the automated stacker system and are tied into all of the emergency stops of the system. The controls prevent the automated shuttle from being sent to the Superlift while it is in use.
It was very important to the marina that our lift had simple controls for their staff to use. Pictured below is the control box for one of the slips. We also included two handheld remote controls with simple “up”, “down” and “stop” controls. Each remote control could control either lift. By pressing the “1/2” button, the remote control toggles between slip 1 and slip 2. The marina also wanted the lifts to be able to run in an automatic mode and this ability was incorporated into the control system.
The limit switches were some of the most important components of the control system. They were used to make sure that the lift always stopped in the proper “up” and “down” positions. If the lift was not in the proper position, the automated shuttle might fall into the water, get stuck, or even damage a boat. Each lift had four powerheads (a single powerhead pictured below), each with their own independent rotary limit switch. The limit switches automatically stop the lift in the proper position. If the lift cradle became out of level, having independent limit switches at the four corners will make the lift cradles automatically self-level.
In addition, the controls utilized lever-style roller limit switches near each rail. These limit switches allowed precise positioning of the lift and made sure that the land side and lift cradle rails were properly aligned.
IMM Quality Boat Lifts was excited to be part of this amazing project. We feel a sense of hometown pride knowing that SWFL has the most advanced marina in the world. Our engineers always enjoy the unique challenges of these large custom projects. Although they are often a labor of love and mostly research and development projects, the knowledge we gain from these projects is invaluable. All of our customers can look forward to some fantastic innovations based on what we learned at Gulf Star Marina. Happy Boating!