Scanjet Macron completes challenging Hanseatic tank level retrofit

Monday, August 01, 2011


Scanjet Macron has completed a challenging tank level gauging system retrofit onboard Hapag-Lloyd Cruises’ MS Hanseatic during the 18-year old vessel’s 13-day dry docking at the Blohm + Voss shipyard in Hamburg. The 184-passenger ship Hanseatic is classed as the world’s only Five Star expedition ship, according to Berlitz Cruise Guide 2011.

The work was part of a comprehensive refit covering more than 780 items, including renovation and modernisation of two cabin decks, the buffet restaurant, sauna, and pool area on the 8,378 tons gross vessel.

“We knew the existing system quite well, but we had no possibility to be onboard before the docking to check what was working and could be used, what was not working, and also how to install the measuring cabinets and interface with the automation system onboard,” says Peter E. Köhler,  Scanjet Macron managing director in Finland.

“Time available for the design and installation of the new system was very short. Together with the chief engineer we found easy-to-access locations for the new cabinets. Supports for the cabinets had to be made and welded and new piping for supply air to the cabinets had to be pulled. We also reduced the number of original small measuring cabinets using our larger cabinets thus saving space and costs.”
 
The new cabinets had to be connected to the old piping and tested for tightness. The tests showed that the piping was in relatively good condition and could be used for the Scanjet system. Some pipes were clogged, but the purging feature proved successful, even when some of the tanks had not been working for years.
 
“The old system communication was very special – the signal was digital with own communication protocol and converted into analogue for interfacing with the automation system,” says Mr Köhler. “We used the existing cabling and upgraded the communication to modern digital Modbus. In order to get the tank levels to the automation system, we developed completely new communication units acting like the ship’s digital automation system sending queries to the measuring cabinets for tank levels. These tank levels were then converted into analogue output signals using our converter cards and connected to the automation system.
 
“After some tuning our system worked perfectly. The tank levels and the draft measuring are now very accurate.”
        
International rules demand that all tanks influencing a vessel’s stability must be sounded for tank level. For practical reasons, remote sounding was developed many years ago on passenger ships because of the large number of tanks and compartments. Essentially, two different systems are in use - the pressure transmitter system, where the tanks pressure transmitters located at the tank side or inside the tank and the electro-pneumatic system where the sensors are in cabinets located in safe area.
 
Once a pressure transmitter inside a tank is damaged, this transmitter cannot be replaced unless the tank is empty and accessible. This means usually that many tanks may have no readings or false readings, and this information cannot be trusted or used in the stability calculations.
 
For fuel tanks, side penetration is not accepted for passenger ships due to fire risks. So also for fuel tanks the pressure transmitter must be located inside the tank. These transmitters are often damaged by pressure shocks when filling the tanks, or by high temperature inside the tanks.
 
Electro-pneumatic systems do not have the problems pressure transmitters have. The sensors are located inside the measuring cabinets, and are easily accessible for checking the performance of the sensors and the system. The sensors are connected to the tanks by copper or stainless steel pipes of small diameter of 8-10mm. Inside the tanks, the diameter is bigger to protect the pipes against mechanical damage.   
Using the ship’s instrument air, the electro-pneumatic sensors measure the fluid pressure inside the tanks. This pressure is converted into tank levels considering the density of fluid inside the tank.

All measuring lines are automatically cleaned by the air pressure, making the system self-cleaning and another important point, according to Mr Köhler, is water ingress and flooding control. “Because our system is blowing air continuously in all tanks, also in the empty ones, there is no risk for clogging of the pipes. This feature is also utilised for water ingress detection in large compartments and voids – because the system is continuously blowing air into these any level change can be recorded and the influence of damage on the ship’s stability assessed immediately. It also provides input for establishing accurate flooding or filling rates for tanks, compartments and voids.
 
“Scanjet Macron’s tank level gauging system has been developed based on the extensive experience we have from various tank level gauging systems, and several hundreds of ships on which we have installed electro-pneumatic and other tank level gauging system,” says Mr Köhler.
 “Our sensors have no drift and in the event of a sensor problem, performance can be checked locally in the cabinet. A damaged sensor can be replaced by the crew in less than five minutes without any calibration needed. All other tanks are measuring the tank levels when the damaged sensor is replaced – no need to shut down the system.
 
“Because all cabinets are on same communication line, we can call up any cabinet and tank from any cabinet, and check the performance of the sensors. There is no need to run from one cabinet to the other to check the performance.
 
“The system is also self-controlling. A sensor watchdog in every cabinet checks the sensor performance. In addition, alarms are shown for sensor failure, low supply air pressure, loss of power, and communication failure.” 

Maritime Today


The Maritime Industry's original and most viewed E-News Service

Maritime Reporter February 2016 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds

Technology

BRP Wins Industry Award for Rotax Innovation

BRP’s Rotax Intelligent Shift and Throttle (iST) system was recognized by the National Marine Manufacturers Association (NMMA) with an Innovation Award in the Jet

Sentinel Launches New Rudder Feedback Unit

Sentinel, a Beier Radio company, has designed and manufactured a new Rudder Feedback Unit (RFU) with many new features, including watertight components and connections

Innovative Equipment Will Help Unload Listing Ship

Following Smit Salvage’s salvage of the stricken ship Modern Express in the Gulf of Biscay, another Rotterdam company has now become involved in the rescue operations.

Shipbuilding

Nordana Sea Delivered to Symphony Shipping

After successful sea trials, M.V. Nordana Sea was delivered to Symphony Shipping on February 11, 2016. Constructed by builder Ferus-Smit in the Netherlands (yard number 419),

James Troop Supplies Engines for 3 Naval Vessels

Liverpool City Region (UK) based ship engine specialist James Troop & Co has won an order to supply Volvo Penta diesel engines for three European naval vessels being built on Merseyside.

OSV Delivered to MC2 in Dubai

Marine Core & Charter LLC (MC2) headquartered in Dubai has taken delivery of the new build PETRA-1, the first of two, 45-meter Fast Offshore Support Vessels in

Passenger Vessels

Interior Facelift for Queen Mary 2

Cunard’s luxurious flagship, the iconic 2,620 passenger ocean liner Queen Mary 2, will undergo an interior refit at the hands of McCue Marine during a 25-day multimillion-pound

USCG to Inspect Storm-damaged Anthem of the Seas

The storm-damaged Royal Caribbean cruise ship Anthem of the Seas is scheduled to return to New York Harbor Wednesday evening where it will be met by a team of inspectors from U.

Royal Caribbean Ship Thrashed by Storm Returns on Wednesday

A Royal Caribbean cruise ship forced to turn back early after being battered by an Atlantic storm was expected to return to its New Jersey port at 9 p.m. on Wednesday (0200 GMT Thursday),

Fuels & Lubes

N.America's First LNG Marine Fuel Terminal Opens

Harvey Gulf announced the opening of the first marine LNG fueling terminal in North America. Less than a year after the delivery of the M/V Harvey Energy, America’s first LNG-powered vessel,

IBIA Celebrates 23th Annual Dinner

Association appoints new board members and sets priorities for the future   The International Bunker Industry Association (IBIA) has appointed three new members

The Next Generation of Hull Performance Management

Hull performance monitoring solutions can offer significant fuel savings potential, a fact that is prompting growing interest from the maritime industry. To spur

Naval Architecture

BAE Systems Awarded £201m to Advance Successor Sub Design

The U.K. Ministry of Defence (MoD) has awarded BAE Systems £201 million to further the design of a successor to the Royal Navy's Vanguard class submarines.   The

The Next Generation of Hull Performance Management

Hull performance monitoring solutions can offer significant fuel savings potential, a fact that is prompting growing interest from the maritime industry. To spur

GTT, DSME Partner for NO96 Max Development

GTT signs a cooperation agreement with Daewoo Shipbuilding & Marine Engineering aiming at the industrialization of its NO96 Max technology   GTT, a designer of

Marine Equipment

Premier Oil and Rockhopper Abandon Ocean Rig Contract

Two of the major British players in Falkland Islands offshore oil development, Premier Oil and Rockhopper Exploration, cancelled a joint venture contract with Ocean Rig UDW.

Teknotherm Marine Moves HVAC Arm to Bergen

Maritime heating, ventilation and air conditioning (HVAC) firm Teknotherm Marine has established a new subsidiary is established with the name Teknotherm Marine HVAC AS.

Sentinel Launches New Rudder Feedback Unit

Sentinel, a Beier Radio company, has designed and manufactured a new Rudder Feedback Unit (RFU) with many new features, including watertight components and connections

Maritime Safety

Berlin film "Fire at Sea" shows Horror of Refugee Crossings

* Movie highlights tragedy of migrant crisis * Filmed mainly on Italian island of Lampedusa * Interleaves lives of islanders with refugees * Film competing for

N.E. Fishermen Warned of Extreme Cold, Wind Chills

The Coast Guard is urging the Massachusetts and Rhode Island fishing fleet to take caution heading into the weekend when life threatening temperatures and wind chills are forecasted.

Maersk to Scrap Ships at India's Alang Beaches, NGO Dismayed

Maersk Line said on Friday it had chosen four shipbreaking yards along India's Alang beaches to handle an increase in vessels that need to be scrapped, to the dismay

 
 
Maritime Careers / Shipboard Positions Maritime Contracts Naval Architecture Pipelines Pod Propulsion Ship Electronics Ship Repair Ship Simulators Shipbuilding / Vessel Construction Sonar
rss | archive | history | articles | privacy | contributors | top maritime news | about us | copyright | maritime magazines
maritime security news | shipbuilding news | maritime industry | shipping news | maritime reporting | workboats news | ship design | maritime business

Time taken: 0.1259 sec (8 req/sec)