Monobuoy range Specification Guide Valid from 2014
Guide to Monobuoys This basic guide has been designed by The Monobuoy Company to help terminal operators tailor and specify their CALM Buoy System requirements quickly and logically.
Table of Contents
The various choices and options are grouped into two categories: Basic configuration
BASIC CONFIGURATION and
OPTIONS
The Monobuoy Company Ltd can also provide full packages for Offshore Terminal Systems. More specifically we offer the following “Terminal to Tanker” packages: Tanker” packages:
• • • • • • •
Pipeline End Manifold (PLEM) Anchoring Systems Fluid Transfer Systems Submarine Hose Systems Floating Hose Systems Hawser Mooring Arrangements Subsea Pipeline Installation
4
Buoy options
14
Anchoring Options
17
Piping Options
18
Systems Options
22
Mechanical Options
29
Summary
35
Typical Buoy Performance
37
BASIC CONFIGURA CONFIGURATION TION The Monobuoy Company offers buoys with different Basic Configurations such as •
Hull Diameter & Height
•
Single or Double Hull
•
Number of Chain Legs
•
Centrewell & Main Slewing Slewing Bearing Size Size
•
Piping Paths and Nominal Diameters
4
BASIC CONFIGURATION – Hull Size The Monobuoy Company offers three hull diameters, 12m, 10m and 8m and a variety of hull heights. The 12 metre diameter buoy is designed for offshore application with water depths of up to 50 metres and beyond. The maximum mooring force is 400 Tonne. This is the most appropriate for the majority of terminals around the world. Usual hull heights are 5.5m, 5m and 4.5m Hull Ø12m H=5.5m
The 10 metre diameter buoy is designed for inshore application with water depths of up to 40 metres, and is ideal for mooring operations that are closer to the shore. Maximum Mooring Force is 250 Tonne. Usual hull heights are 5m and 4.5m Hull Ø10m H=5.0m
The 8 metre diameter buoy is designed for special locations which require low water depths and for use on smaller ship mooring operations. Maximum Mooring Force is 100T . Usual hull heights are 4.5m and 4m. Hull Ø8m H=4.5m
5
BASIC CONFIGURATION – Hull Size The Monobuoy Company offers buoys with different diameters and heights to suit a wide variety of locations and operating criteria.
Standard hull diameters available are 8m, 10m and 12m versions with standard heights from 3.5m up to 5.5m. The diameter is usually selected based upon the tanker size and weather conditions (i.e. expected mooring force) while the height is selected based upon the water depth (the deeper water required more anchor chain and hence more displacement to support the weight). The following table summarises the buoy diameter and height.
8m
Hull Diameter 10m
12m
Mooring Force
100T
250T
400T
Skirt Diameter
11m
14m
16m
Typical Uses
Specialist locations, tankers
Hull Height (m) 5.5 5.0 4.5 4.0 3.5 ○
– Possible
Inshore, tankers
Offshore, up to DWT 350,000 VLCC
Water Depth (m) ●
●
●
>40 15-40 <15
>40 10-40 <10 ●
– Not Possible
>50 20 - 50 <20
● ◊ -
Possible but not advised
● ◊
6
BASIC CONFIGURATION – Single or Double Hull
For operations in difficult conditions such as arctic waters the hull can be built as a Double Hull, providing at least 12 individual watertight compartments providing the maximum security in case of accidents.
Conventional Single Hull with 6 or 8 watertight compartments
Double Hull arrangement with 12 or 16 watertight compartments. Full access is provided inside double hull for inspection
7
BASIC CONFIGURATION – Anchoring Chain Leg Configuration
3 × 2 LEG PLAN 12 LEG PLAN
Can be installed on either an 8 anchor pattern or equally on a 6 anchor pattern.
Can be installed on an anchor pattern of 3 pairs of chains, often used by other manufacturers turret buoys.
8 LEG PLAN 6 LEG PLAN Can be installed on a 6 anchor pattern. This is the most usual configuration today.
Can be installed on an 8 anchor pattern. This was used extensively in the past with the older type lower grade chain 8
BASIC CONFIGURATION – Anchoring Chain Leg Configuration Several options are available for anchoring chain pattern. The most common pattern today, and the one recommended by Monobuoy is one of 6 chains evenly spaced. Older buoys were often moored with 8 evenly spaced chains. Some buoys are moored with 6 chains grouped into 3 pairs with each pair at 120° spacing. Finally, it is possible to supply a buoy with 12 chain attachment points to allow the buoy to be installed on either a 4, 6 or 8 chain pattern (equally spaced). Chain Pattern
8m Hull
10m Hull
12m Hull
4 evenly spaced (at 90 )
○
◊
◊
6 evenly spaced (at 60 )
○
○
○
8 evenly spaced (at 45 )
●
○
○
6 grouped into 3 pairs (at 120 )
●
○
○
12 (6 & 8 evenly spaced)
●
●
○
°
°
°
°
○
– Possible
●
– Not Possible
◊ -
Possible but not advised
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BASIC CONFIGURATION – Piping Many piping configurations are possible to transport crude oil, refined products, LPG, methanol, water and a wide range of other fluids. The most common systems operate at low pressure (<21 bar) although small bore high pressure systems (up to 8 ”, 300 bar) can also be made. DESIGN PRESSURE For the low pressure systems the design pressure can either be 19.7 bar (ANSI 150# flanges) or 50.7 bar (ANSI 300# flanges) The 50.7 bar system allows for surge pressures to be accommodated. Note a standard hose with a Working Pressure of 300 psi (21 bar) can absorb a surge pressure of 31.5 bar. FLUID PATHS The buoy can accommodate several discrete fluid paths to enable the transfer of different fluids in any direction. For a crude import/export buoy it is common to have a single path with a large nominal bore, typically 28” or more. For a buoy used at a products transhipment terminal, 4 or 5 paths can be used in order to separate the various products. Where paths larger than 24” are used the path is divided into two pipes so that standard 24” marine hoses can be used. Note the paths can have different pressure ratings
Buoy fitted with 2 fluid paths - 28” path (2 x 20” inlets/outlets) - 12” path (1 x 12” inlet/outlet) 10
BASIC CONFIGURATION – Piping FLUID SWIVEL & PIPE RUNS The buoy is fitted with a fluid swivel to pass the fluids between the piping on the turntable and the piping on the hull. This swivel can have one or more paths, up to a practical limit of 5. The paths can be small high pressure ones or large low pressure ones. For paths larger than 24” it is common to have twin outlets and twin piping systems which allow the use of compact pipe runs and valving, standard marine hoses and balances the high side loads on the swivel.
21 bar Product Swivel double path
Buoy with 5 Fluid Paths 11
BASIC CONFIGURATION – Piping, Common Low Pressure Systems (<33 bar/ 450 psi)
1st path
2nd Path
Nom Bore
4th Path
Min.Buoy Size/ Centrewell Size
Piping
34”
2 × 24”
○
10m/3.2m
28”
2 × 20”
○
10m/3.7m
34”
2 × 24”
Piping
Piping
Nom Bore
Hollow Bore
Nom Bore
28”
Nom Bore
3rd Path
Piping
16”
1 × 16”
○
12m/4m
12”
1 × 12”
○
12m/4m
16”
1 × 16”
○
12m/3.7m
12”
1 × 12”
○
12m/3.7m
○
12m/3.7m
◊
12m/3.2m
2 × 20”
20”
1 × 20”
16”
1 × 16”
12”
1 × 12”
12”
16”
1 × 16”
12”
1 × 12”
8”
1 × 8”
8”
○
– Possible
●
– Not Possible
◊ -
1 × 8”
Possible but not advised
12
BASIC CONFIGURATION – Centrewell & Main Slewing Bearing Size The next choice is the diameter of the centrewell (and hence the main slewing bearing diameter) and whether the centrewell is dry or open at the bottom. A closed, dry centrewell allows more complex piping systems to be installed as there is more dry volume, however there are several drawbacks. Submarine hoses are more difficult to install with Pull-in tubes needed which can corrode and cause centrewell flooding. A water-tight cover is required over the centrewell to avoid ingress of water inside the dry centrewell.
The centrewell diameter is mainly governed by the number and size of submarine lines, whilst the main bearing diameter limits the mooring force. Typically a 3.7m diameter centrewell can comfortably house pipework for 2 x 20” and 1 x 16” submarine lines.
Centrewell Diameter
The following Table shows the various combinations available. Moonpool / Main Slewing Bearing diameter
Open or Closed
8m Hull
10m Hull
12m Hull
Normal
2.5m
3.2m
3.7m
Optional
3.2m
3.7m
4.0m 13
CHOICE OF OPTIONS The Monobuoy Company offers its basic buoys with only the items either required by Regulations and Rules or items which we consider necessary for basic operations. Standard Items include • • • • • • • •
Navigation unit comprising Lantern, Battery and Solar Panel. Passive Radar Reflector 10T Pneumatic Maintenance Winch with sheaves and guides for hose pull in. Butterfly valves in the Centrewell and Turntable piping on every line. Hand Bilge Pump in each Buoyancy Compartment. Two Manual Fire extinguishers Two Lift rings 1T Lifting Davit for Swivel Dome maintenance
However many Options can be fitted as listed on the following pages
14
OPTIONS LAYOUT - 1 Swivel Leak Recovery Tank
Hydraulic and/or Electric Swivel to feed Buoy Hull and PLEM Fog Horn
Navigation Lantern
Simple Protection Frame
Passive Radar Reflector Battery Box Simple Multi-Bolt Manhole Cover
50T Chain Tensioning Tripod
Sounding Plug
50T Chain Tensioning Multi-Part Block
Mooring Lugs 10T Air Winch Boat Landing “Jump” Platform Automatic “Ratchet” Chain Stoppers
Polymer Chain Hawser Bearings
Overboard Ballast Arm and Boat Landing
Red = Optional Blue = Standard
15
OPTIONS LAYOUT - 2 Monorail and Trolley for Material Handling Partial Protection Frame
Flushing By-Pass
Davit for Material Handling to Supply Boat
Hose Pull in Guides
Single or twin Mooring hawser bridle (Standard on 400T Buoys)
Overboard Pipe Protection Frame
Divers Platform
Vertical Welded Steel Fenders Red = Optional Blue = Standard
16
ANCHORING OPTIONS – Chainstoppers The chainstoppers are all located in the skirt, outside the hull for easy maintenance and accessibility. Three different types of chainstopper are available.
The traditional cone type
This is the type fitted to older buoys.
The automatic ratchet type. This type has largely superseded to the cone type due to its ease of operation.
Twin-axis ratchet type. Used almost exclusively on deep water buoys. Its main advantage is it reduces “out-of-plane” bending fatigue on the chains
PHOTO
Available for all buoy types
Available for all buoy types
Only available on 12m diameter buoys 17
PIPING OPTIONS – Buoy Valve Types
BUOY VALVE TYPES The standard type of valve supplied on the buoy is a manually operated butterfly valve. These are installed either side of the swivel, in the centrewell and on the buoy turntable to allow isolation of the floating hoses following flushing and for maintenance of the swivel and expansion pieces. The following Options are available: • • •
Actuated Butterfly Valves Manual Ball Valves Actuated Ball Valves
Should a telemetry system be fitted, then it is possible to monitor the position of the valves from shore and open and close the valves remotely.
Manual Operated Ball Valve on Buoy Turntable
18
PIPING OPTIONS – Subsea PLEM Types
Subsea PLEM TYPES The standard type of valve supplied on the subsea PLEM is a manually operated subsea ball valve. These allow full isolation of the buoy system including submarine hoses. The following Options are available: •
•
•
Actuated Ball Valves with umbilicals up to the buoy Piggable PLEM with barred Tee’s and 5D bends (for twin lines system) Pig Receiver/Launcher mounted on the PLEM (for single pipeline)
Piggable PLEM (twin lines system) with Actuated Ball Valves
Should a telemetry system be fitted, then it is possible to monitor the position of the subsea PLEM valves from shore and open and close the valves remotely. Also Pig signalling can be transmitted to the buoy through the umbilical and then on to shore via telemetry. 19
PIPING OPTIONS –Automatic Swivel Leak Tank
SWIVEL LEAK RECUPERATION TANK As the product swivels age they start to leak slightly. As part of our commitment to preventing pollution, Monobuoy fits as standard a Swivel Leak Recovery Tank. This tank has a sight glass and a hand pump to pump the leaked fluid back into the product lines. An Option is to fit a 24V electric pump that can either be controlled manually or automatically with level switches. Should a telemetry system be fitted then the tank level and frequency of pump operations can be transmitted back to shore.
Swivel Leak Tank with pneumatic pump
20
PIPING OPTIONS – Surge Prevention System With long export pipelines and high flow pumps there is a danger of damaging pressure surges occurring should there be a sudden closure of a valve on the loading tanker. Modern hoses can accept up to 30 bar (450 psi) pressure surges and the buoy piping can be selected as a 50 bar system using ANSI 300 lb flanges. However in many cases the surge pressure can exceed this and then a surge protection system can be installed on the buoy. The system comprises a fast acting highflow relief valve and a surge tank in one of the buoy compartments. Signalling (via telemetry) can indicate to the shore that a surge has occurred and to trip the pumps. Alternatively the shore pumps can rely on their own high pressure tripe. The surge tank can be fitted with a pump to empty the tank following a surge. 21
SYSTEMS OPTIONS – Hawser Load Monitoring Telemetry can be installed on the buoy to transmit both information from the buoy and commands to the buoy from the shore base or a hand-held unit with the Mooring Master. The most simple system is used to transmit realtime hawser loads to the mooring master and shore base. This system comprises a hand-held unit a loadcell on the buoy with signal processing unit and radio transmitter and a shore base unit connected to a PC.
Buoy with Hawser under load
The distance from Buoy to Shore can be several nautical miles depending upon the radio frequency chosen.
7” Hand Held Unit for Mooring Master 22
SYSTEMS OPTIONS – Telemetry The Telemetry System can be expanded to include a multitude of sensors, actuators etc. such as: •
Hawser Load Monitoring
•
Battery Voltage and charging status
•
Valve Position and control
•
Meteorological data
•
Buoy Motions
•
Swivel Leak Tank Status
•
Greasing System Status
•
Surge Tank and Valve Status
•
Video Surveillance Camera
•
Navaids status & control
•
Chain angles and tension
•
Buoy Position
•
Floodlight Control
Telemetry Block Diagram
Typical Shore Base PC Display 23
SYSTEMS OPTIONS – Automatic Bearing Greasing System The Main Slewing Bearing and Product Swivel Bearings require regular greasing. To ease the monotonous chore Monobuoy has developed, with the industries leading manufactured of lubrication systems, an automated greasing system. The system uses a small electric DC motor to pump the grease through metering valves to all the grease points on both the Main Slewing Bearing and the Swivel bearings. The cycle runs daily this ensuring the bearings are always fully packed with grease. Alternatively a system can be installed that uses a single point to connect a manual (or pneumatic) pump carried onto the buoy by the maintenance crew.
Grease Lines installed on Swivel
Main Slewing Bearing Grease lines inside Turntable Box Structure 24
SYSTEMS OPTIONS – Lighting To allow safe operation during night-time the buoy can be fitted with low-power LED flood-lighting.
This can be useful in the more Northerly areas where winter brings long hours of darkness or where terminals have a very high occupancy and need to berth during the hours of darkness.
25
SYSTEMS OPTIONS – Navigation Aids As standard a buoy is fitted with a stand-alone Lantern/Battery/Solar Panel assembly. This system can be expanded to include the following additions: •
Low Power LED Lantern
•
Fog Horn (short or long range)
•
Fog Detector for auto switching of the Fog Horn
•
AIS Transponder
•
Racon Transponder
Fog Detector ½ Mile Fog Horn
Standard Unit
As the systems expands there is a need to install a separate battery box, heavy-duty charging systems and a power control module. Charging systems are usually Solar Panels but can also be Wind Generators or Diesel Engines.
Battery Box
The entire system can be integrated into the telemetry system to provide remote monitoring and control
Solar Panels 26
SYSTEMS OPTIONS – Electric and Hydraulic Swivels
HYDRAULIC & ELECTRIC SWIVELS
In order to accommodate equipment mounted either in the buoy hull or on the PLEM, such as hydraulic operated valves, it is necessary to mount a hydraulic and/or electric swivel on the Fluid Swivel. This necessitates a “hollow bore” swivel to pass the hoses and cables through the centre.
Electric Swivel
Hydraulic Swivel
Product Swivel
27
SYSTEMS OPTIONS – Power The basic buoy only has a single navigation lantern and this is powered by a self-contained battery and solar panel. If larger electrical system are selected then it becomes to increase the power generation and battery size by using a combination of more solar panels, wind generators or a small diesel genset.
If hydraulic power is required (for valve actuation, pumping or winching) then we have developed a very efficient 24V DC Hybrid power pack.
Hybrid HPU for Deep Water buoy
This pack uses accumulators which are charged when there is an excess of power being generated by the buoys generation system. The pack also has provision for an AC motor or air motor so that during chain tensioning operations the high demand of the winch can be met by a portable genset or compressor on the workboat. 28
MECHANICAL OPTIONS – Deck House
Some buoys over the years have been fitted with Deckhouses, fully enclosing the equipment inside.
This gives the advantages of protection from the elements, a personal refuge and increased security. However there is a significant disadvantage in that maintenance is more difficult and the deckhouse is considered an enclosed space making personnel entry more difficult.
Turntable Buoy fitted with a Deckhouse
29
MECHANICAL OPTIONS – Rope Guard The basic buoy has a simple hoop type rope guard mounted over the mooring bridle to prevent the mooring bridle and triangle plate impacting the swivel should a mooring hawser fail. Some buoys are fitted with a tubular rope guard cage that cover the entire buoy to try to protect all the buoy equipment in the event of a hawser failure. However, Monobuoy does not recommend this as these cages often get hit by the work boats superstructure causing extensive damage to radar, radio antennae etc. If a tanker bumps the buoy, its anchor can get caught on the cage and cause extensive damage and deformation to the cage, which often makes subsequent operations of the buoy difficult.
Small Rope Guard
Simple Mooring Bridle Guard
Full Rope Guard 30
MECHANICAL OPTIONS – Lifting & Hoisting 1 The basic buoy has a simple swinging davit mounted adjacent to the fluid swivel on the turntable. This davit is used with either a chain block or snatch block and winch to lift the swivel dome (for swivel maintenance)
An option is to replace the davit with a single runway beam mounted along the centreline of the turntable piping. This runway beam can then also be used for lifting valves, expansion pieces and other equipment. On the ballast platform, a rotating davit can be fitted to allow transfer of load from the runway beam to a workboat.
Rotating Davit Runway Beam
Standalone Overhead Trolley Bean
Trolley Beam and Davit as part of a Protection frame 31
MECHANICAL OPTIONS – Lifting & Hoisting 2 (Chain tensioning) The basic buoy is not fitted with any method of installing or re-tensioning the anchor chains as many operators have a small crane barge locally available.
Winch Wire
However two options exist for tensioning chains from the buoy.
6-part Fixed Block
A tripod can be installed at the ballast platform with a six-part block and tackle system fed to the 10T maintenance winch. This provides 50T pull for chain tensioning.
10T Winch Removable grating giving the Travelling Block access to the Chain Stopper An alternative is to use a specially developed double-drum two speed winch which has a small 10T wire for maintenance and hose installation tasks and a larger 40t wire which can make a direct pull in the chains. The advantage is that a chain can be pulled up either from the seabed of from a supply boat in one continuous operation unlike the block and tackle system, making the buoy “self-installing” 32
MECHANICAL OPTIONS - Buoy Access The basic buoy has a boarding ladder, with heavy duty fenders on either side, on the turntable opposite the floating hoses. This boarding ladder also incorporates the ballast arm which balances the weight of the turntable piping. Access to the buoy is either via this ladder or directly onto the hull deck from the bow of a workboat.
Several options are available for boarding ladders. Custom access ladders can also be designed for specific clients needs.
Standard Simple Ladder
Lower Ladder with Jump Platform at height of Support Vessel Gunwhale
No Ladder 33
MECHANICAL OPTIONS – Diving Operations The basic buoy has no protection frame around the overboard piping or ladders.
Several additional options are available: •
•
•
•
Protection Frame around the overboard piping. (shown alongside) Ladders down either side of the Protection Frame GRP Grating Divers Platform below the floating hose connection flanges. Additional platform at the intermediate spool connection
In addition, the basic buoy has two diver access ladders down the inside of the centrewell (open moonpool type buoy only)
34
SUMMARY – BASIC CONFIGURATION
Standard HULL SIZE HULL CONSTRUCTION ANCHOR LEGS PRESSURE RATING PIPING PATHS CENTREWELL SIZE
12m x 5m Single Hull 6 equally spaced legs 21 bar with ANSI 150# flanges Path 1 - 34" NB (2 x 24) Path 2 - 16" NB (1 x 16) 3.6m diameter
Alternatives 8m or 10m diameter and heights from 3.5m to 5.5m Double Hull 4 or 8 equispaced, 12 (6 and 8 legs) or 3 pairs of legs 50 bar with ANSI 300# flanges Multitude of alte rnatives from singl e 38" NB to 5 x 12" NB
4.0 m diameter
35
SUMMARY – OPTIONS Chain Stoppers
Standard
Alternatives
Cone Type
Automatic Ratchet Dual axis type Ball valve Hydraulic Actuation Piggable from shore or from PLEM using divers Hydraulic actuation from buoy Automatic pump Surge valve and tank with or without powered pump. Load cell with telemetry to shore and tanker Telemetry system with a multitude of options to transmit & receive from shore and tanker. Single point manual system Fully automatic system LED buoy floodlight system Fog Horn, Fog Detector, AIS, Racon Hydraulic and/or Electric Swivels Full Decdkhouse over turntable Partial Deckhouse over the Centrewell Partial or Full Rope Guard 10T hydraulic winch 50T tripod and sheaves and blocks for chain tensioni ng 40T continuous pull chain tensioni ng winch Overhead runway beam and locking trolley with overboard davit Ladder and jump platform No ladder or overhanging arm Protection frame and two ladders down to divers platform Addition of intermediate platform Additional Solar panels, wind generator and batteries 24V DC HPU with AC and pneumatic input ◦
◦
Butterfly, sandwich type Buoy Valve Actuation Manual PLEM Non piggable PLEM valves Manual Ball subsea type Swivel Leak recovery tank Fitted with manual pump Surge Protection System Hawser Load Monitoring Telemetry Buoy Valve Type
Bearing Greasing
Manual multipoint
◦
◦
Floodlights NavigationAids Aux. Swivels Deck House
Lantern, Battery, Solar Panel -
◦
◦
Rope Guard Lifting and Hoisting
Only Mooring Bridle Guard 10T pneumatic winch, centrewe ll davit and various guides for submarine and floating hose pull.
◦
◦
◦
◦
◦
Buoy Access
Simple ladder on ballast platform
Diving
Two ladders in moonpool. No divers ladder or frame around the overboard piping. Small battery and solar panel integrated with navigation lantern
◦
◦
Power
◦
◦
◦
◦
36
TYPICAL BUOY PERFORMANCE 8m Buoy Water depths Tanker Size Floating Hose lengths Significant Wave height Current Wind Speed Significant Wave height Current Wind Speed Significant Wave height Current Wind Speed
10 m Buoy
12 m Buoy
Typical Performance 10m to 30m 15m to 40m 20m to 80m Up to 50,000 DWT 50,000 to 100,000 DWT Up to 350,000 DWT 130-210 m 210-240 m 240-310 m Typical Berthing Limits 1.5 m 2.0 m 2.5 m 1 knot 1.5 knot 1.5 knot 20 knots 25 knots 30 knots Typical Operational Limits 3.5 m 4.5 m 5.5 m 1.5 knot 1.5 knot 1.5 knot 30 knots 40 knots 50 knots Typical Survival Conditions (no tanker moored) 7m 8m 9m 3 knot 3 knot 3 knot 80 knots 80 knots 80 knots
37
NOTES
38
