Zabezpieczanie przed ogniem drewnianych obiektów zabytkowych

The protection of wooden heritage buildings against fire, biodeterioration, robbery and vandalism is one of the most important tasks in the field of cultural property preservation. In Poland and other European countries, the most popular wood-made objects are historical wooden churches (Catholic and Orthodox ones), rural huts, cottages, sheds, barns and wooden wind mills which are like open air museums. Wood is the most common raw material that was used for the construction of these objects since ancient times. Generally these wooden objects are wholly combustible, they are mostly located beyond towns and difficult to guard and exposed to risk of setting on fire. Not everywhere there is a sufficient supply of water from water tanks and fire hydrant network. Moreover, there is a lack of good access ways for fire brigade vehicles and no fire detecting systems were installed in many of these objects. Unfortunately, fire retardant application is insufficient or totally absent in these heritage buildings. This manuscript presents general possibilities of the application of modern technology of fire retardancy systems intended for the protection the heritage objects against fire disaster. None or only minimal influence on an ancient object wood is the advantage of the above systems. The fire safety strategy for wooden buildings and historical sites requires an agreement and compromise between the point of view of art. Historians and conservators and that of fire-fighting experts.Drewno było najczęściej używanym surowcem do konstrukcji obiektów od najdawniejszych czasów, które w czasie jego użytkowania narażone jest na biodeterioracje i całkowite spalenie w wyniku pożaru. Drewniane obiekty zabytkowe są całkowicie palne, a na dodatek często zlokalizowane poza miejskimi ośrodkami z utrudnieniami do ich dostępu przez straż pożarną. Stąd zabezpieczenie przed pożarami takich obiektów jest bardzo ważne, tym bardziej, że pomimo rozwoju techniki i technologii, pożary tych obiektów zdarzają się coraz częściej. A zatem czy aktualnie istnieje możliwość takiego przeciwogniowego zabezpieczenia drewnianych obiektów, aby „w dyskretny” sposób zabezpieczyć je przed rozprzestrzenianiem się ognia z wykorzystaniem nowoczesnych środków ogniochronnych? Obniżenie palności i szybkiego rozprzestrzeniania się płomieni w tych obiektach stwarza nadzieję na zapobiegnięcie kompletnego ich spalenia. Przy doborze środków ogniochronnych i systemów zabezpieczenia należy brać pod uwagę również to, by te środki i systemy nie wywierały niekorzystnego wpływu na wygląd, higroskopijność i trwałość zabezpieczonego drewna zabytkowego. Za wielce efektywne uznaje się miedzy innymi transparentne powłoki pęczniejące w warunkach pożarowych, które to odcinają dostęp tlenu z powietrza poprzez wytworzenie izolacyjnej, niepalnej piany zapobiegającej penetracji ognia wewnątrz elementów drewnianych. Zastosowanie pasywnych systemów ochrony ogniowej, które mogą być połączone z zastosowaniem biocydów w zabytkowych budynkach drewnianych takich jak kościoły, skanseny, obniżając ilość nieszczęśliwych pożarów tych obiektów

PROTECTION OF IRAQI CULTURAL HERITAGE WITHIN THE POLISH STABILISATION MISSION

The article was inspired by a publication which appeared in the British daily “The Guardian”, containing fragments of a report by Dr. John Curtis, a British Museum expert, dealing with the unsatisfactory condition of certain historical monuments in Babylon. Dr. Curtis placed the blame for the existing state of things on the American and Polish soldiers stationing at the Camp Alpha base, located in the Babylon archaeological site by Marine units after the fall of the Hussein regime. This sensational press information produced a worldwide “storm” in the mass media. The authors of the presented article refer to the charges formulated by the British researcher and describe the presence of Polish soldiers in the Babylon military base within the context of the protection of the world famous cultural heritage. They propose multiple arguments demonstrating the superficiality of some of the assessments in the report of the British expert, and cite facts indicating the document's falsehoods. Finally, they confront the more than ten-pages long and sparsely documented text by the British author with the ascertainments presented in an all-sidedly documented report about the current state of the Babylon archaeological site (a text of more than 530 pages long and 1 140 photographs), prepared in wartime conditions by Polish archaeologists-specialists concerned with the protection of cultural heritage. An additionally noteworthy fact is that the British author was familiar with the Polish document and even used it, but did not refer to its contents. The initially outlined problem comprises a point of departure for explaining the motives of Poland’s access to a mission of salvaging threatened Iraqi cultural property. The authors point out that the Republic of Poland and Iraq are signatories of international conventions on the protection of cultural property, a fact which urged the Polish Minister of Foreign Affairs to file at the UNESCO forum a declaration about rendering assistance to Iraq. The article focuses on the protection of Iraqi cultural heritage, realised as part of a stabilisation mission conducted by Polish archaeologists acting within the structure of the Polish Military Contingent (PKW). Examples of contacts between the Polish Ministry of Culture and representatives of Iraqi cultural institutions and provisional authorities as well as scholarships and training financed for the Iraqis, bring the two side closer and lead to a revival of mutual cultural relations. By presenting the specificity of the central-southern stabilization zone, which remains under Polish supervision, the authors depict the enormous devastation of the archaeological sites and museum, committed by well organised and armed groups of robbers. This damage – the outcome of crime-inducing phenomena caused by the war – was not prevented either by the coalition armies or the insufficiently organised and equipped Iraqi Antiquities Service. Conspiciuous examples include the museums in Baghdad and Babylon, whose invaluable collections were looted. The presented results of an archaeological reconnaissance carried out in several provinces of the stabilisation zone by Polish archaeologists-specialists testify that damage to archaeological sites and ancient ruins was also incurred by the local population, whose members gather and use archaeological substance as valuable building materials. The authors also discuss the findings of on-the-spot inspections, which upon several occasions took place at the Babylon archeological site (the location of the Alpha military base), and were conducted both by Polish archaeologists and an independent team of international experts, including Americans, Poles and Iraqis. Their ascertainments showed that alongside military factors connected with stationing the troops, an essential impact on the state of the preservation of the Babylon monuments was exerted by plunder and natural conditions, such as precipitation and a periodically high state of subterranean water. The publication mentions various undertakings and procedures carried out by the command of the multinational division, intent on protecting the historical monuments and minimalising the losses, i. a. archaeological monitoring. Much attention is devoted to the transference of the Alpha base to the Iraqis. The article cites a special plan of a stage-by-stage handing over of Babylon, devised by Polish military commanders and archaeologists to ensure the safety of the ancient town’s monuments after the departure of the multinational subdivision. The authors stress that the Polish Military Contingent, acting as part of the Multinational Division Centre-South, is the only one among of the national contingents whose structure from the very beginning included archaeologists-specialists dealing with the protection of cultural heritage. A tangible result of their work is the realisation – in coordination with the Iraqi Antiquities and Heritage Services – of 23 projects dealing with repairing, reconstructing, and renovating Iraqi historical monuments as well as outfitting the Iraqi services for the protection of historical monuments, including a newly created archaeological police, at a total cost of 700 000 dollars from a fund at the disposal of the commander of the Multinational Division CS. In the closing part of the article its authors portray the unique educational and preventive solutions applied by the Polish Military Contingent for the purpose of eliminating among its soldiers all temptations and opportunities for taking out of Iraq any sort of historical monuments, evidence of the local cultural heritage. The publication ends with an attempted balance sheet of the accomplishments of the Polish mission in the light of media facts

Numerical Investigation of the Influence of Aerodynamic Loads on the Resonant Frequency of a Compressor Blade Made of EI-961 Alloy

The aim of this work was to numerically determine the influence of aerodynamic loads on the value of the resonant frequency of the compressor blade. The object of the research was the 1st stage compressor blade of the PZL-10W engine. As part of the research, analytical calculations of the resonance frequency were performed and compared with the literature ones (first, second, and third forms of forced vibrations). In the next step of the investigation, a computational model of the compressor stage (fluid domain and rotors) was built and FSI analysis was performed. This analysis was based on CFD modeling of the state of aerodynamic loads on the blade surfaces, and then these values were imported as external loads for the structural analysis, which was the basis for the modal analysis, in which the resonant frequency of the first three vibration modes was determined. As part of the analyzes, both the influence of aerodynamic loads and the rotational speed of the compressor rotor were verified. Thus, it was possible to evaluate the influence of both the rotational speed (and the arising centrifugal force) and the influence of the emerging aerodynamic load. The results obtained will allow for the assessment of the impact of the aforementioned operating conditions of the aircraft engine on the resonance frequency, which in turn may translate into the durability of critical components of the aircraft engine

Technological Aspects of a Reparation of the Leading Edge of Helicopter Main Rotor Blades in Field Conditions

The Polish Air Force operates more than one hundred helicopters of the Mi family (manufactured by Mil Helicopters), equipped with metal main rotor blades. The main rotor blades are among the most stressed components of these structures. For this reason, they are subject to more frequent inspections during operation than other components. One type of damage detected during inspections is the local disbonding of fragments of the anti-erosion layer from the leading edge. This harmless-looking damage is very dangerous, since it quickly leads to the complete detachment of the layer. The leading edge, unprotected by the metal cover, erodes rapidly. The detached layer, when thrown away at high speed, endangers other parts of the helicopter, such as the tail rotor, and may cause damage to other helicopters if flying in formation. The technology supplied by the manufacturer to date has not encompassed the field repair of this type of damage. Therefore, efforts were made to develop repair technology for rapid repairs of blades in field conditions during missions of the Task Force White Eagle in Afghanistan. This article presents the concept of repair technology feasible in field conditions and presents the results of post-repair edge tests. Test results to identify the materials used in the construction of the trailing edge are also presented. The results of materials testing facilitated the development of technological processes, and, in the future, will aid the selection of a substitute bonding paste system with similar parameters that are essential for repairs

Technological Aspects of a Reparation of the Leading Edge of Helicopter Main Rotor Blades in Field Conditions

The Polish Air Force operates more than one hundred helicopters of the Mi family (manufactured by Mil Helicopters), equipped with metal main rotor blades. The main rotor blades are among the most stressed components of these structures. For this reason, they are subject to more frequent inspections during operation than other components. One type of damage detected during inspections is the local disbonding of fragments of the anti-erosion layer from the leading edge. This harmless-looking damage is very dangerous, since it quickly leads to the complete detachment of the layer. The leading edge, unprotected by the metal cover, erodes rapidly. The detached layer, when thrown away at high speed, endangers other parts of the helicopter, such as the tail rotor, and may cause damage to other helicopters if flying in formation. The technology supplied by the manufacturer to date has not encompassed the field repair of this type of damage. Therefore, efforts were made to develop repair technology for rapid repairs of blades in field conditions during missions of the Task Force White Eagle in Afghanistan. This article presents the concept of repair technology feasible in field conditions and presents the results of post-repair edge tests. Test results to identify the materials used in the construction of the trailing edge are also presented. The results of materials testing facilitated the development of technological processes, and, in the future, will aid the selection of a substitute bonding paste system with similar parameters that are essential for repairs