TFR Dictionary
Definitions
float·ing dock
/ˈflōdiNG däk/noun
A Floating Dock (or Dock System) is Defined as:
‘A buoyant platform secured to a flexible anchoring system, that allows the dock to rise and fall as water levels change - while maintaining topside stability.’
Floating Docks are Designed to Work with the Environment to Achieve Stability
Floating Dock systems are still thought of by many to be unstable and flimsily made. But, the truth of the matter is, modern polyethylene floating docks perform better in varied environments, and have a longer lifespan than fixed (stationary) docks. Like the movement of a skyscraper in high winds, floating docks are made to be sturdy, yet flexible. Tall buildings must sway (however minimally) to avoid damage, floating docks are designed to work in much the same way, they flex to reduce the impact of the water.
Many definitions of floating docks reference they “float on the water’s surface” - but this is not accurate. Floating dock systems achieve flotation by leveraging scientific principles to establish a water stance that maintains stability, regardless the environment, and adapts with depth changes as they occur.
How is this accomplished?
let’s check out the science!
Most Floating Docks use one of two scientific principles to achieve their water stance (also known as ‘Float Profile’):
1. Hydro-static Surface Tension
➤ This Float Profile engages hydro-static surface tension (or pressure). It’s made possible by designed hollow cavities that trap air between the dock and below the surface that creates a powerful suction that holds the dock in place, under the water surface - not on top of it.
2. Buoyancy Principle
➤ This float profile is governed by Archimedes’ Principle of buoyancy. Stability is achieved when the dock’s weight displaces water, creating an equal and opposing upward buoyant pressure that stabilizes the structure.
Anchoring
Connectors
Flotation
➤ Actively responds to environmental changes
➤ Reduce impact by Absorbing and Displacing Shock
➤ Designed using float principles to establish Water Stance
While each component has specific functionality - it cannot achieve stable flotation without the combined effort of all 3 working in tandem.
Reactive Anchoring, Flexible Connections, Flotation Design.
Each floating dock component has to be rigid, yet flexible, in order to maintain its water stance while limiting impact from the environment.
These 3 Components are the foundation for floating dock systems - let’s have a look at exactly HOW they work..
Floating
Dock
Anchoring
A key feature of Floating Dock Systems is the varied anchoring types that allow for application to virtually any waterfront.
Each anchoring option can be used on its own or in combination with others to maximize security and optimal functionality. This includes standard Pilings (posts), Dead Weights, Stiff Arm Brackets, Hinge Adaptors and Bottomless Stand-off Brackets.
Piling (Post) Anchoring
The most common type of anchoring for floating docks is the Pilings (post) setup. This anchoring option is ideal for most waterfronts without steep drop-offs or inhospitable bottoms. These can be used in depths up to 20 ft (6.1 m).
A Piling (posts) system is the sturdiest floating dock anchor option. Depending on the dock system brand, Posts either connect to the sides along the perimeter of the dock, or via cutout holes (a less used option) in the dock itself, from which the post is dropped through to the bottom.
The post setup typically has 3 pieces: the post/piling, the sheath/bracket, and an auger (screw point) on the bottom of the post to drill into the water bottom.
Dead Weight Anchoring
Floating Docks with dead weight anchoring is used for deep water or lake beds with bottom consistency that cannot receive pilings (posts).
Dead weights can also be combined with other anchoring types to adjust for waterfront environments with steep drop-offs. In that case, dead weights can be used at the deep end, while the shore side (shallow portion) can be secured with posts.
Dead weight setups quite often utilize additional anchoring types for additional security and stability. In deep water scenarios, the additional anchoring is most often Stiff-Arm or Bottomless Stand-off brackets close to the shore. Mixing the anchor types for dead weight setups is recommended for extra stability, especially if the dock is receiving watercraft or is in an area with constant winds and movement.
Stiff Arm Anchoring
Floating Dock Stiff-arm brackets are ideal for deep water environments like channels or rivers. When water depth exceeds the dead weight anchoring option, Stiff-arm anchoring fills the gap (literally and figuratively).
Stiff-arm brackets are the ideal choice for temporary or seasonal dock systems. They can be used in conjunction with every other anchoring option to enhance security or connect to an existing dock.
Bottomless Stand-Off Anchoring
Similar to Stiff-arm brackets, the bottomless Stand-off anchoring system is ideal for steep drop-offs and deep water environments. These can be customized and are generally used for less extension into the water, whereas the Stiff-arm brackets are used for longer waterfront gaps.
Stand-off anchoring is frequently used in smaller dock platforms, gangways or PWC/Boat Ports in marinas.
Floating
Dock
Connectors
The connectors in floating dock systems have three primary responsibilities, to keep the dock sections securely connected, allow them to move independently, and to absorb and/or disperse impact from the dock.
Floating dock systems are not designed to simply withstand the force of water like a fixed (stationary docks), they’re purposefully designed to actively protect the dock by absorbing and redistributing it.
SHOCK ABSORPTION
➤ Floating dock connectors not only affix the docks to each other, they are the protection for the docks themselves. No matter how slow the current or size of a body of water, its movement power should never be underestimated. Watercraft wake, chop, storms and wind, do not take it easy on docks.
The first job of floating dock connectors is to insulate the dock sections from damage, by absorbing and dispersing shock. Each brand and design of floating addresses this differently, but the focus remains the same. Floating docks are not designed to withstand currents and chop like stationary docks. Instead, they’re built to absorb and process this pressure to ensure the dock pieces are protected.
PLATFORM SECURITY
➤ Floating dock connectors keep the sections (dock pieces) secured in a platform. A simple job with a not-so-simple design requirement. Floating dock connectors must keep the platform secured as one, while simultaneously allowing each piece to move independently as the water acts upon it. It may sound contradictory, but it makes sense and works!
The Second job of floating dock connectors is to hold the dock’s shape with a connection that still allows each section to operate independently.
FLEXIBLE MOVEMENT
➤ Because floating dock systems are in constant motion, the connectors must be designed for Rigid Flexibility. They must secure the dock sections, but with enough flex to allow movement, yet rigid enough not to break during the twisting and torque of the water’s impact.
The Third job of floating dock connectors is to maintain the platform’s shape and stance while flexing when required, to allow each section to move with the current as it flows through, under and around the dock.
Floating Dock Connectors Secure, Flex and Protect
The connectors in floating dock systems are more than the pieces that make your design possible. They are designed to perform 3 jobs simultaneously and on-demand. They must keep the dock sections securely fastened, flex to allow the dock sections to move independently, and intercept and disperse the twisting torque/shock from water movement.
The stability of a floating dock system is entirely dependent on the function of its connectors.
Floating
Dock
Flotation
Floating Docks do not simply sit on the surface and float without control. Modern floating dock systems are designed to actively engage with the water to ensure active stability.
The design of floating docks goes far beyond how it looks and the available colours. Most floating dock designs incorporate the flotation directly into the dock sections themselves.
Float Profile - How Floating Docks Maintain their Water Stance
Not all floating dock types incorporate their flotation into the design, some have external flotation affixed (pontoon floating docks). For our purposes here, we’re discussing polyethylene (plastic) floating dock systems. These are dock designs that combine their flotation into the dock platform itself. Polyethylene docks incorporate their flotation into the dock sections, featuring air cavities and/or foam inserts.
Polyethylene floating docks have achieved impressive flotation capacity, strength and stability since the early 1990s. Varying in brand and design, plastic floating docks have become the standard - not the less appealing alternative.
A floating dock’s Float Profile is determined by is flotation type, dock section design and the materials in the construction. Let’s take a look at these design elements and how they affect Float Profile and performance.
FLOTATION TYPE
➤ Flotation type is determined by the design of the dock sections itself. Polyethylene (plastic) floating docks engage either displacement flotation or hydro-static surface pressure.
Cube (standardized) Docks & Pontoon Style Dock systems use: Displacement Flotation
Single-mould Dock systems use ‘Hydro-static Surface Tension: Pressure Flotation
Pressure Flotation
This type relies on water pressure. The deeper an object goes, the more pressure is created by the water pushing against it. This pressure difference between the top and bottom of the object pushes it upward. It’s all about pressure building from depth.
Displacement Flotation
A dock based on Archimedes' principle floats because it displaces a volume of water. The more water it displaces, the more upward force the water pushes back with. This upward force holds the dock in place, keeping it stable on the surface