By Gabriele Assmann and Ronnie Schmidt. The four-masted steel barque Passat was one of eight sister ships built by the Blohm & Voss shipyard on behalf of the shipping company F. Laeisz and was launched in 1911. As an identical sister ship to the Peking which will soon be transferred from New York to Hamburg, the Passat was purchased by the Hanseatic City of Lübeck after 50 years of service and was moored at the Priwall Harbour in Lübeck-Travemünde in 1960.
The barque was initially only used as a museum ship but was then soon also utilised for accommodation and event purposes – still up until today: The Passat is now considered a landmark in Travemünde and is admired by more than 60,000 visitors a year. Up to 102 people can stay overnight in the more than 40 cabins and experience the special flair of this ship that has been a protected historical monument since 1978. Two larger event rooms and a meeting room offer space for parties catering for up to 180 people. The Hanseatic City of Lübeck also offers people the opportunity to get married on the Passat, which up to 60 couples take advantage of each year.
The article was published in FeuerTRUTZ International, issue 1.2017 (January 2017). The printed article also shows a floor plan of the fire protection concept for the intermediate deck.
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A diverse range of potential hazards came to light during a fire prevention inspection held by the Lübeck Fire Department, whereupon the Lübeck Port Authority and the School & Sport Department of the Hanseatic City of Lübeck approved the development of a holistic fire protection concept. The goal was to also enable the ship to be used for accommodation and event purposes in the future. In addition, the planning and implementation of the required fire protection measures should take place during ongoing operation.
The special characteristics of this task became clear right at the start of the investigations – alongside the fact that the project dealt with neither a building nor a seaworthy vessel: The Passat has been moored at the harbour as a floating yet stationary facility since 1960 and is no longer seaworthy. Therefore, it was not possible to carry out the assessment in accordance with statutory building regulations nor international maritime regulations such as the IMO-SOLAS regulations (International Maritime Organization – Safety of Life at Sea).
This situation continued when identifying the responsible authority: The Lower Building Control Authority were not responsible and the Water and Shipping Authority were also not the applicable body. Following extensive discussions, a team consisting of the owners, the Lübeck Port Authority as the specialist authority for harbour issues, the preventive fire protection division of the Lübeck Fire Department, as the fire protection authority, and the engineering office, as the developers of the required fire protection concept, was finally formed.
As the normal catalogue of requirements from the state building regulations or special building regulations was not applicable, it was necessary to define and agree the safety goals independently. Following comprehensive surveys by the Lübeck Fire Department, a cold smoke test was carried out in the lower deck areas of the Passat for this purpose. The difficulties faced when dealing with a listed four-masted barque became clear when it had to be concluded to the surprise of all those involved that even a small fire event could lead to extensive problems with smoke. The reasons for this were the very low ceilings, the narrow corridors and the connections between different deck areas via companionways. In the event of a real fire, there would be no possibilities for rescuing people in the cabins located below deck as a result: Smoke was detected in almost all areas of the 115 m long ship on up to four decks within just a few minutes (see figures 2 and 3).
In addition to defining and securing smoke compartments, it was thus clear from the beginning that early detection and an alarm system, as well as effective smoke extraction for the use of the existing emergency routes, was absolutely essential. The narrow widths of the rescue routes were also an important aspect of the risk analysis because the routes in the area of the event rooms would be used by large volumes of people all at once, while at the same time serving as the access routes for the Lübeck Fire Department to tackle the fire (see figure 4).
Evacuation calculations were developed for these areas to assess the widths of the emergency routes. The routes were then partially rearranged.
Due to the structure of the Passat with steel decks and a steel bulkhead, any possibility of preventing the spread of the fire by arranging space-enclosing walls or ceilings was excluded: These types of ship components are not capable of sufficiently preventing an increase in temperature on the side of the wall or deck not exposed to the fire. As a the four-masted barque is a protected historical monument, it was also not permitted to strengthen or make significant changes to the affected components so that it was necessary to accept significant deficiencies when it came to fighting fire.
Due to the fact that the ship is regularly used by numerous people who are unfamiliar with the ship, it was necessary to place a special focus on organisational fire protection (see below). The following measures were defined at an early stage:
- Developing and securing defined smoke compartments
- Installing comprehensive fire detection technology with a corresponding alarm system
- Labelling and lighting of the emergency routes
- Installation of an effective smoke extraction system
As expected, their implementation proved to be difficult because ultimately it was not possible to fall back on any applicable legal regulations. For this reason, the planning team was thus expanded to include recognised specialists for the approval of the technical safety equipment before the implementation of these measures. This step was taken to ensure that solutions were developed that would later be approved.
In order to produce the defined smoke compartments, it was not possible to use standard insulation systems approved by the building authorities because in a steel ship like the Passat there are no solid, mineral-based walls and ceilings available to act as enclosing components. Consequently, safety goal-oriented solutions had to be found that were sufficiently smokeproof for the affected steel bulkhead and steel deck of the ship. Therefore, existing openings in the bulkhead and deck were plugged with mineral wool with a melting point of more than 1000 °C, intumescent fire protection foam and intumescent coatings.
In order to mechanically secure these systems in place, the ship’s crew also added additional fittings in many areas to make them secure. Larger openings were welded shut or sealed by the ship locksmith and carpenter from the Passat crew using individually manufactured plates, while corresponding seals and overhead door closers were added to the doors in these sections. Final smoke tests carried out across multiple smoke compartments demonstrated that they were sufficiently leaktight in the early phases of a fire.
Active fire protection
The installation and fitting of the fire detectors and their cable systems, as well as the emergency power supply lines, also required individual, safety-goal-oriented solutions from the participating companies and planners and the experts tasked with their approval (see figure 5).
The smoke detectors for the fire detection system could not be screwed directly into the steel deck of the ship in most areas because this contained the caulking for the ship’s deck and the screws would have resulted in leaks. In most areas, the fire detectors were fitted to the steel frames (frame for the hull of the ship) using brackets and beam clamps or threaded bolts.
In difficult to reach areas, wireless fire detectors were fitted to the steel deck with magnets. The size and quantity of the magnets needed on the base of the detector was determined based on the existing thickness of the paint on the steel components of the ship.
It was also not possible to install the cable systems for the fire detection system or the emergency power supply lines in accordance with the specifications in the Sample Cable System Guidelines (Muster-Leitungsanlagenrichtlinie) or in line with the certificates of suitability issued by the building supervisory authorities. In agreement with the experts tasked with issuing approvals, these were fitted in place on the hull of the ship using clamps and in some cases adhesive methods. In order to guarantee the integrity of the cables for a sufficient period of time, cables with their own functional integrity were used and laid in protective tubes.
The small room sizes and the ventilation ducts running over all decks of the Passat represented a serious disadvantage in the event of a fire because of the fear of the early and extensive distribution of smoke. The ventilation ducts in the Passat consist of thick-walled steel pipes, which are open at one end in the lower deck, the so-called “stowage”. In addition, the deck sections above this level each have a larger pipe diameter and open annular gaps. The pipes lead above deck and are covered with a mushroom cap or finished with a swan’s neck design.
These existing pipe systems provide the only existing connection between the lower deck areas and the outside atmosphere and it was possible as part of the fire protection optimisation measures to turn them from being a disadvantage to being an advantage:
Following in-depth investigations and detailed planning, smoke gas fans were manufactured for the existing pipes, which could be positioned in the pipes just below the steel mushroom caps. The mushroom caps were detached for this purpose and fitted with new screw connections to ensure accessibility to the motors and repair switches. The open portions of the open pipe sections in the lower decks were adapted where required with custom-built perforated plates.
In those areas where no ventilation pipes were available, special solutions were developed. The upper deck, which has an existing skylight hatch to the poop deck, was fitted, for example, with a system in the skylight and the hatch on the deck was appropriately retrofitted in line with the ship’s protected monument status and given an actuator with a limit switch (see figure 6).
The supply air feed for the total of eleven smoke gas fans had to be individually produced for each smoke compartment. In some sections, it was possible to use existing ventilation pipes, while in other sections the existing openings firstly needed to be created for this purpose. For example, the opening for the anchor cable at the stern of the ship was fitted with a louvre damper with a limit switch and protective cage. The flow rate of the smoke gas fans was set in the individual smoke compartments for an approximately tenfold exchange of air at smoke gas temperatures of 400° C.
As the existing ventilation pipes were also required for the utilisation of individual rooms e.g. showers below deck and the event rooms, the new smoke gas fans also have to be capable of being operated for ventilation purposes. Frequency converters were thus integrated into the fan controls for this purpose.
As it was not possible to install an emergency power generator, the power supply to the systems in the event of a loss of voltage was converted so that it now works via a sprinkler pump switch on the ship’s main control panel. This was done in agreement with the experts tasked with issuing approvals and the fire protection authority of the Lübeck Fire Department.
Approvals and testing
The building regulation experts approved the installed technical safety systems as being free of defects after the completion of individual tests. The tests were based on the fire protection concept and mutually agreed test results and the detailed specifications of the parties involved: the Lübeck Fire Department, the Lübeck Port Authority and the engineering office responsible for the planning.
In order to visualise and verify the effectiveness of the systems, multiple smoke tests in different smoke compartments were then carried out. These tests demonstrated the effectiveness of the installed smoke extraction systems: Despite a considerable amount of smoke being generated by the cold smoke machine, it was possible to extract the smoke in the affected area within 60 to 90 seconds.
Visibility in the rescue and firefighting routes was rated as being very good. Due to the distribution of the fans and the corresponding supply air openings, the generated air flow meant it was even possible to keep neighbouring smoke compartments free of smoke when doors were open, which significantly improves the use of the emergency routes and the ability to effectively extinguish the fire. The systems will be tested on a recurring basis in future in accordance with the Schleswig-Holstein Testing Ordinance and kept in good condition via maintenance contracts.
Organisational fire protection
In order to ensure organisational fire protection, staff numbers have immediately been increased especially for events and during the night. Furthermore, a Fire Safety Officer was appointed and trained, with the aim of managing the entire set of measures in the future on behalf of the Passat crew.
For the ongoing use of the ship as accommodation, the users of different decks were handed interim cabin plans, evacuation and rescue plans and fire safety regulations in parts A and B with information about the specific risks on the ship and the available evacuation and rescue possibilities (see figure 7). In addition, an evacuation drill with different scenarios and carefully selected disruptive issues of differing size was completed to raise the awareness of the crew. The members of the crew then evaluated the evacuation drill together in a meeting and shared the information with everyone.
The development and implementation of the fire protection concept for the four-masted barque Passat in Travemünde is certainly a one-off solution that would be difficult to transfer to other projects – except for perhaps its sister ship, the Peking. At the same time, this project nevertheless demonstrated that even apparently totally unregulated buildings or objects could be provided with a suitable safety concept – if there is close cooperation and responsible decisions are taken by all those involved.
It was possible to implement the concept during ongoing operation, without it leading to any noteworthy interruptions in the operation of the ship. From the perspective of the engineering office responsible for the planning, this exceptional project also provided those involved with a wealth of new knowledge and, despite the three year term of the project also a high level of motivation, which is not least thanks to the constructive cooperation of all those participating in the project, especially the crew of the Passat.
The fire protection concept for the fourmasted barque Passat was awarded a special prize at the award ceremony for the German industry prize “Fire Protection of the Year 2016”.
Dipl.-Ing. Architect Gabriele Assmann: Managing Partner of Assmann Schmidt Ingenieure; Expert Planner for Preventative Fire Protection (EIPOS)
Dipl.-Ing. Architect Ronnie Schmidt: Managing Partner of Assmann Schmidt Ingenieure; Expert for Preventative Fire Protection (EIPOS)
Other project workers:
- Dipl.-Ing. Katharina Peters
- B.A. Anna Einsle
- M.Eng. Tom Jatzek
- Dipl.-Ing. Silke Nissen
The article was published in FeuerTRUTZ International, issue 1.2017 (January 2017).
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