Every year, fires aboard roll-on roll-off (ro-ro) ships result in costly damage to ships and their cargo and, fortunately less frequently, in tragic loss of life. On the other hand, statistical studies have shown that a large proportion of major fire accidents originated in the vehicle decks. To improve the issue of vehicle-deck fires on board ro-ro ships, a performance-based simulation tool was developed to quantify the consequences of these fires on people, ship, and cargo. This tool combines a deterministic computational fluid dynamics model to assess the fire consequences in the vehicle decks and open areas of the ship; a stochastic network model in the accommodation spaces; and a deterministic evacuation model to evaluate the consequences of fire to people on board. This article briefly presents the numerical tools used and their extension to ro-ro ships, then the results obtained for selected fire scenarios on two generic ro-ro ships, varying the location of the fire source, wind conditions, and including one accidental situation due to a loss of integrity of the insulation at the ceiling of the deck from which the fire originated and one scenario where some openings of this deck were closed. People evacuation was simulated for the accidental scenario. Fire consequences are further evaluated in terms of human survivability, in compliance with the life safety performance criteria of the International Maritime Organization, damage to the ship and cargo. A qualitative comparison with reported accident data is presented to assess the consistency of model results.

A series of model scale experiments were conducted to study the fire development in a ro-ro deck with various opening geometries. The experiments were performed in a 1/8 reduced scale model with a heptane pool fire as fire source. Experimental results show that both the ventilation factor and the opening position affect the fire development. The critical opening ratio for the fire to self-extinguish is 4%, with the opening locating at the bottom of the side walls while no self-extinction is found for other tests. A higher opening position and a larger opening height provide better flow exchange between the deck and the ambient, but this effect is only obvious for 4% opening. Numerical study shows that Fire Dynamic Simulator used with default simple settings underestimates the fire development and yields an early extinction when fire self-extinction occurs. For freely developed fire with large openings, FDS gives more close results to experiments.

The International Convention for the Safety of Life at Sea (SOLAS) recognises five different fire-extinguishing system solutions for ro-ro spaces on ships; manually activated water spray systems (Resolution A.123(V)), automatic sprinkler or deluge water spray systems and automatic nozzle or deluge water mist systems (MSC.1/Circ.1430), high-expansion foam systems and gas fire-extinguishing systems (FSS Code). A review of potential commercially available alternative systems, their expected performance efficiency and water consumption was made. Based on this review, two alternative fire-extinguishing systems were identified: Compressed Air Foam Systems (CAFS) and foam-water sprinkler/spray systems. Fire suppression performance testing of water spray systems according to the Resolution A.123(V) and MSC.1/Circ.1430, a CAFS and a foam-water spray system were conducted. The water spray system per MSC.1/Circ.1430 had superior performance while the system per Resolution A.123(V) and the foam-water spray system limited the fire size to some degrees. The CAFS provided limited fire suppression performance.

The International Maritime Organization, through its correspondence group on fire safety, has underlined the need for more scientific studies regarding the performance of A-60 boundaries in case of a ro-ro space fire, especially to prevent fire spread to accommodation spaces. RISE has carried out the RoBound project in order to answer to this need. The goal of the project was to clarify the performance of “state-of-the-art” fire boundaries between ro-ro spaces and accommodation spaces or other ro-ro spaces, and to give recommendations on how sufficient fire containment is ensured.In order to obtain realistic exposure reached during a fire within a ro-ro space, simulations were performed using Computational Fluid Dynamics (Fire Dynamics Simulator).The first step was to model representative ro-ro spaces as well as representative cargo. Two representative ro-ro spaces were then defined: closed and open ro-ro spaces with open ends. Concerning the cargo, the ro-ro spaces were assumed fully loaded with trucks or fully loaded with cars. Moreover, two types of thermal insulation were chosen, A-60 and A-30. The highest temperature given for each simulated case was then compared with time-temperature curves for designing fire safety.Almost all comparisons showed that the hydrocarbon time-temperature curve fits better to the highest temperature reached in the simulations. The hydrocarbon time-temperature curve is more severe than the standard (cellulosic) time-temperature curve according to ISO 834, used for type approval of thermal insulation. Experimental tests were then carried out to observe the performance of A class insulation when exposed to the more representative hydrocarbon time-temperature curve in a cubic furnace. The fire insulations were mounted on steel plates with different thicknesses (5 mm, 6 mm and 12 mm).Tests results showed a significantly reduced fire integrity when exposed to the hydrocarbon time-temperature curve, meaning that it took less time to reach the maximum temperature elevations required by the FTP Code (140 °C for the average temperature elevation and 180 °C for the highest temperature elevation). The reduction was about 50%, depending on the thickness of the steel plate. These results apply for stone wool. Glass wool fire insulation was also used in the tests but it was deteriorated when exposed to the high heat exposure in accordance with the hydrocarbon time-temperature curve.

This is the report from the literature study of the RoBound (Ro-ro space Boundary fire protection) project. RoBound is carried out by RISE Research Institutes of Sweden AB.The ro-ro ships have a large longitudinal space where cars, trucks and other cargo can be rolled on and rolled off. Despite improved fire protection regulations, many fire accidents have occurred on ro-ro ships and there are no signs of them diminishing in number or magnitude. During a review of the fire safety regulations, the IMO correspondence group has particularly pinpointed the need for additional experimental data or results of scientific studies regarding:- The performance of A-60 boundaries in case of a ro-ro space fire, especially to prevent fire spread to accommodation spaces; and- The performance of A-0 boundaries in case of a ro-ro space fire, especially to prevent fire spread between ro-ro spaces.In this process, Sweden has moreover underlined the issue of the smoke tightness of A-class divisions with doors. While smoke tightness is a requirement for A-class divisions, the fire resistance test method in the Fire Test Procedures (FTP) Code is not designed to evaluate hazards associated with smoke spread. RoBound purpose is to clarify the performance of “state-of-the-art” fire boundaries between ro-ro spaces and accommodation spaces or other ro-ro spaces, and to give recommendations on how sufficient fire containment is ensured. RoBound aims to strengthen competence and influence regulation development regarding fire divisions of ro-ro ships.The main result from the literature study is that :- The concept of horizontal fire zones, allowing ro-ro spaces and special category spaces to be as long as the whole ship, was introduced in 1967 according to resolution A.122(V), but was made mandatory long time after. In SOLAS 1974, entered into force in 1980 the main vertical zones was included in the regulation.- The land based method will not be used in RoBound since some smoke tightness solutions are based on an intumescent sealing joint. In order to be activated, the joint needs high temperature which is not reach in the land based standard.- Hose ports, also denoted “Cat holes”, are used on board with different experiences. Some think it works fine, other that it more problem. Level of maintenance vary from almost nothing to a lot of hassle. It is concluded that they reduce the amount of smoke spreading through the door compared with have a wedge and doorway open.- Doors to the ro-ro space is not perceived as smoke tight, and so are not lift doors. Crew is aware of the importance of well closing fire doors, checks are made daily.- Fire insulation in ro-ro spaces can be damaged by loading of trailers or during maintenance work. There can also be water damage (testing of drenchers, cleaning or by rain) and general wear and tear. Damaged insulation happens but not too often so it is not experienced as a problem for the crew.

This report is the final report from the research project RO5. The report summarises the results from the research project RO5. The report consists of summary from a literature study, from computer simulations and from model scale tests. This, together with results from full scale demonstrational test (documented only in this report) leads to the conceptional solutions and recommendations presented in this report. The project focused aim was to investigate the effects of ventilation on fire development in ro-ro spaces with different ventilation conditions.

Important conclusion from the literature study is that ventilation is primary to prevent flammable and other harmful gases from accumulating in the spaces, and the mechanical ventilation is not designed to be functional in case of fire. It is a must for the crew to gain knowledge about the ventilation system (i.e. fans, inlets and outlets) and its capacity from tests and experiences. It is important that guidelines, rules and routines are established for using the ventilation system in typical conditions (loading/unloading etc.) and that it is documented and passed on to provide guidance for the ship's crew.

One of the most important conclusions from the model scale tests and numerical simulation study is that distinct limitation is found for 4% opening of space sides (natural ventilation) for the fire self-extinction to occur. This is dependent on the height and shape of the opening. For the mechanical ventilation case, in case of fire, stopping the ventilation is the best way to reduce the fire intensity. The tests show that mechanical ventilation is vital for the fire to continue to burn. The recommendations aim at giving advise concerning ventilation in case of fire and how to deal with the ventilation at different ro-ro spaces.

The International Maritime Organization, through its correspondence group on fire safety of ro-pax ships, has underlined the need for more scientific studies regarding the performance of boundaries in case of a ro-ro space fire, especially to prevent fire and smoke spread to accommodation spaces. Following these discussions, Swedish Flag State has underlined the issue of the smoke tightness of doors in A class divisions. While smoke tightness is a requirement for A class divisions, the fire resistance test method in the FTP Code is not designed to evaluate hazards associated with smoke spread.RISE has carried out the RoBound project to meet this need.To increase the understanding of this weakness in the FTP Code, RISE has performed experimental tests of two almost identical doors. The only difference between the two doors was the presence or not of an intumescent joint between the leaf and the frame of the door, intended to prevent the passage of smoke. The doors were exposed to the test for fire boundaries in Part 3 of the FTP Code, which exposes specimens to a simulated fire by a temperature increase according to the standard fire curve ISO 834.A modification of the standard experimental rig was added and consisted of the addition of a canopy above the tested doors to gather and measure the rate of carbon dioxide to quantify the amount of smoke leaking from the doors. This set up of canopy and measurement rig was taken from the standard EN 81-58 which is applied for elevator doors acting as fire barriers.The results of the tests showed that both doors marginally failed the A-60 integrity criteria since there was presence of a sustained flame at the unexposed side before 60 minutes of test. However, both doors satisfied to the insulation criteria by maintaining a rise of temperature lower than 140 °C in average at the unexposed side. The main difference between the doors was that the door with the intumescent joints presented a rate of smoke leakage which was almost half of that of the fire door without intumescent joints.This result clearly shows the importance of evaluating the smoke tightness of A class doors during testing and the need

A novel intumescent (carbonization, acid donor and foaming) fire retardant that mimics carbon nanotubes was introduced into bitumen roofing and characterized using cone calorimetry as the main analytical tool. The experimental results indicate that 18% (by mass) attapulgite mineral (ATTP) mixed with base bitumen decreased the peak heat release rate per unit area (pHRRPUA) by 10%. Further, incorporation of melamine coated ammonium polyphosphate (MAPP) decreased the pHRRPUA by 52% and a mixture of these (3:1, ATTP:MAPP) decreased the pHRRPUA by 25% as compared to adding CaCO3 as a filler. The residual mass loss after the cone test was also improved with up to 3%. The indication of a positive synergistic flame retardant effect of the ATTP-MAPP mixture is supported by thermogravimetric analysis. The addition of this rod-like mineral improved the general fire retardant properties of the base bitumen and increased the viscosity. Therefore, the polymer-modified bitumen with both fire retardant and rheological properties (providing mechanical strength) is a promising novel approach in the design of bitumen roofing membranes. 

A combination of cone heater experiments and asymptotic analysis was used to determine the moisture content of Nordic spruce with varying degree of drying. The fuel moisture content was measured by weighing the specimens before and after a drying procedure in an oven. A high-flux asymptotic solution from an integral model established that the ignition temperature from the experiments (directly linked to the intercept heat flux) was constant for both the dry and the moist wood. As a result, one simple equation was developed that can be used to determine the time to ignition for a piece of wet spruce from the time to ignition of dry wood. This simple correlation, combined with models giving the fuel moisture content of wood from humidity and temperature of air surrounding, can be used as an engineering equation for monitoring the ignition propensity of timber.

RISE Research Institutes of Sweden have carried out fire tests to evaluate fire fighting methods in case of a fire involving alternative fuel vehicles (AFV) in a ro-ro space. This report presents how selected fire fighting methods were practically evaluated for their possible to use in ro-ro spaces. The results can be applied for safer and more efficient manual fire fighting operations, which is increasingly important when carrying AFVs.

The fire tests were performed in a large fire test hall at RISE Fire Research in Borås and the fire load was represented by a steel mock-up of a personal vehicle with a propane test rig, creating a fire of 4 MW. Steel walls, representing adjacent vehicles, were fitted with thermocouples to measure the temperature 0.6 m from the mock-up vehicle. Extinguishing media were applied between the mock-up and the steel wall on the left-hand of the vehicle and the temperature reduction was measured. The results present the reduction coefficient achieved by different systems, i.e. the heat blockage effect achieved by the systems. A high reduction coefficient indicates that the system has a high capacity to reduce heat exposure and prevent fire spread to an adjacent vehicle.

For handheld system, the highest reduction coefficient was achieved by the Industrial system and the FRS system (but only with a high water flow rate), providing both a reduction coefficient of 0.64. Reduction coefficient on the opposite side of the vehicle, from where the water was applied, also varied between the different systems. The highest reduction coefficient on this side was achieved by the high pressure 60 system, providing a reduction coefficient of 0.34. For water curtain system the Hose provided the highest capacity to reduce heat exposure on both side of the vehicle.

How different tactical options could optimize the performance of the handheld systems was evaluated primarily by visual observations. After the first part of the test was conducted (measuring blockage effects) the operator was able to oscillate the water spray, both up and down and over the vehicle. The operator also approached the vehicle from the front, at an angel of 45°, in order to observe the effects with respect to cooling or suppression. By varying the technique, it was possible to optimize the cooling effect on both sides of the vehicle, but the operator must be able to adjust cone angle and water spray pattern to maximize the effect. During this part of the tests it was possible to observe that some systems had a limitation in capacity with respect to cooling or suppression, especially if the pressure was low or if it had a low water flow rate. The water curtain systems were not able to affect the other side of the vehicle, which indicates the need of positioning the nozzle or hose on at least two sides of the burning vehicle to be able to efficiently prevent fire spread.

A field test (outdoor) was also conducted to evaluate the practical usability of the tested systems. A simulated ro-ro space was built up on a fire rescue training field where relevant crew tried different tactical options with the different system. It was found that a semi-rigid hose with a small inner diameter is much easier to handle in most cases but must be compared with desired capacity of pressure, water flow rate and throw length. A hose with a larger inner diameter will have greater stiffness which proved to be useful when trying to position water curtain nozzles. The tests showed that it is possible to position water curtain nozzles to prevent fire spread, but the hose most be further developed to be able to use in ro-ro spaces.