Hazard Identification

Hazard Identification

      As Manuele (2010) argued we perceive hazards at varying levels of risk to our safety; what one person views as high risk, another may not. The ethical conduct and profitability of organizations relies on occupational hazards identified and managed within competent risk assessment processes. These occupational hazards can be physical, chemical or physiological that leads to workplace accidents and impact on firms’ productivity and profitability (Ramsay et al., 2006; Lees, 1996; Hollmann et al., 2001). But not all hazards are known and risk management is also about dealing with the unknown.

Hazards can be determined by using assessment methodology which is include following documents and information:

i.              Any hazardous occurrence investigation reports;

ii.            First aid records and minor injury records;

iii.          Workplace health protection programs;

iv.          Any results of work place inspections;

v.            Any employee or students complaints and comments;

vi.          Any reports, studies and test concerning the health and safety of employees;

vii.        Any reports made under the Regulation  of Occupational Safety and Health Act, 1994;

viii.      The record of hazardous substances; and

ix.          Any other relevant information.

For fire to occur there must be a source of ignition, fuel and oxygen. If all three (3) elements are present and in close proximity, then the fire risk could increase as a result. In the average premises fire hazards will fall into the first two (2) categories, while the oxygen will be present in the air in the surrounding space. Occasionally oxygen can be found in chemical form (oxidising agents) or as a gas in cylinders or piped systems.

Potential sources of ignition are :

i.              Naked flames: smokers materials, matches, pilot lights, gas/oil heaters, gas welding, cookers;

ii.            Hot surfaces: heaters, engines, boilers, machinery, lighting (for example, halogen lamps), electrical equipment etc.; and 

iii.          Hot work: welding, grinding, flame cutting. 

Other than that, hazard can be worse when the building is not really prepared for fire. Examples like :

i.              No training among the staff about fire drill and fire fighting equipment;

ii.            Firefighting device is not well equip;

iii.          Design of the building are not save for evacuation (Fig. 3); or

iv.          No proper Standard Of Procedure (SOP) when fire occurred.

There are considered several types of situation during fire such as fall from stair during evacuation of building; time evacuation; firefighting equipment working; and knowledge of occupant using firefighting equipment.

Hydrogen : Something Interest

The word of hydrogen is from the Greek word hydro (water), and genes (forming). Hydrogen was recognized as a distinct substance by Henry Cavendish in 1776.  Hydrogen is the most abundant of all elements in the universe. The heavier elements in the periodic tables were originally made from hydrogen atoms or from other elements that were originally made from hydrogen atoms. Hydrogen is available in almost every corner of the universe, amounting to nearly 90% of all the atoms. It is found in the star. Through fusion processes hydrogen are combined to form helium, and in the process release massive amounts of energy

Hydrogen is the first element in the periodic table. In normal conditions it’s a colorless, odorless and insipid gas, formed by diatomic molecules, H2. The hydrogen atom, symbol H is formed by a nucleus with one unit of positive charge and one electron. It’s one of the main compounds of water and of all organic matter, and it’s widely spread not only in Earth but also in the entire universe. At normal temperature hydrogen is a not very reactive substance, unless it has been activated somehow; for instance, by an appropriate catalyser. At high temperatures it’s highly reactive.

  

Hydrogen has the following properties:

Properties	Value
Atomic number	1
Atomic mass	1.007825 g.mol -1
Electronegativity according to Pauling	2.1
Density	0.0899*10 -3 g.cm -3 at 20 °C
Melting point	- 259.2 °C
Boiling point	- 252.8 °C
Vanderwaals radius	0.12 nm
Ionic radius	0.208 (-1) nm
Isotopes	3
Electronic shell	1s1
Energy of first ionisation	1311 kJ.mol -1
Discovered by	Henry Cavendish in 1766*

Table 1 Properties of Hydrogen

Hydrogen Uses:

There have been numerous cases of hydrogen application. Hydrogen often called the energy source of the future as it can be easily found in overabundance in the entire universe. It has been widely used in the following industries: Petrochemical, Transportation, Metal, Aerospace and weapon.

In the area of transportation, it is often used to propel everything from land speed record-breaking vehicles, as fuel cell to power passenger cars, buses and forklifts. In a lot of countries it is also used to power a lot of vehicles as a mean of alternative energy source. In a fuel cell, hydrogen and oxygen are converted into electricity through an electrochemical process, and the only waste is water. As hydrogen and oxygen are available easily in the natural environment, they can be fed continuously thus producing a continuous supply of electricity. This process is clean and environmental friendly. The electricity generated can then be used to proper motor and stored in battery if needed.

This extreme energy from hydrogen is used to fuel rockets and power life-support systems and computers in space environment. The fuel is used in the form of liquid hydrogen. Liquid hydrogen (LH2 or LH₂) is the liquid state of the element hydrogen. Liquid hydrogen is also used to power non-nuclear based submarines like Type 212 submarine, Type 214 submarine. Also concept hydrogen vehicles have been built using this form of hydrogen. [2] In Europe, there have been many applications of hydrogen in the transportation such as: Clean Energy Partnership  (CEP); and London Hydrogen Partnership (LHP).

Clean Energy Partnership (CEP) is one of the largest and most innovative hydrogen projects in Europe. It is intended to show that running on hydrogen and building a hydrogen infrastructure will be trouble-free. Various energy companies such as Linde, Shell, Statoil, Total and Vattenfall are participating in the project, as well as car manufacturers such as BMW, Daimler Benz, Ford, Opel, Toyota and Volkswagen.

Hydrogen-powered vehicles are already a reality, and mass scale production to achieve economic of scale are in the planning of almost every major car manufacturer. [5]Toyota already announced plan to launch hydrogen car in 2015. Cities like London and California have prepared for this future vehicle by launching hydrogen-based projects and passing bills to fund hydrogen stations for massive scale of use.

Hydrogen is used widely in petrochemical industries. Hydrogen is essential in today’s refining industry for upgrading heavy crude oils into refined fuels, and helping to meet increasingly tight transportation fuel specifications. The petroleum and chemical industries use a massive amount of H2 hydrogen in the refinery processes. The number one application of H2 is the processing of crude oils, and in the production of ammonia. For petrochemical plants, the key consumers are hydrodealkylation, hydrodesulfurization, and hydrocracking. H2 is used as a hydrogenating agent, particularly in increasing the level of saturation of unsaturated fats and oils (found in items such as margarine). It is also used in the manufacture of hydrochloric acid and methanol and as a reducing agent of metallic ores.

In welding and metal fabrication industries, it is also used to enhance plasma welding and cutting operations, hydrogen gas is commonly mixed with argon for welding stainless steel. It is also used in metal sintering and annealing. Metal sintering is a method for creating objects from powders, including metal and ceramic powders. It is based on atomic diffusion.

Why hydrogen was preferred?

LZ-129 Hindenburg airship was built by Zepplin Company in the late 1920s for transatlantic passenger transportation purpose. It was originally designed to be lifted by helium. As helium’s inert non-flammable nature makes it very practical to be used in lighter-than-air (LTA) flight. But helium being relatively rare and heavier than hydrogen, it was not as economical as hydrogen for mass transportation purpose due to fewer payload than it can carry. In comparison, hydrogen can carry extra 50% of useful payload then helium. For that reason, hydrogen was ultimately being used. Additional lifting capacity allows more passenger cabins to be added and more postal mails able to be carried.

My Overview on Hindenburg Incident

The Zeppelin that flew from Europe across the Atlantic Ocean was known as the Titanic of the air. As the huge Zeppelin approached Lakehurst, New Jersey, the large aircraft burst into flame and went down in a burning heap of fire. The burning Zeppelin fell from the sky. It only killed 35 people, but injured many more.

There are some hypotheses that can be considered:

1.1        Sabotage Hypothesis:

1.1.1  Hugo Eckener; At the time of the disaster, sabotage was commonly put forward as the cause of the fire, initially by Hugo Eckener, former head of the Zeppelin Company and the "old man" of German airships. Eckener later publicly endorsed the static spark hypothesis.

1.1.2  Capt. Max Pruss; Another proponent of the sabotage hypothesis was Max Pruss, commander of the Hindenburg throughout the airship's career. Pruss flew on nearly every flight of the Graf Zeppelin until the Hindenburg was ready. In a 1960 interview conducted by Kenneth Leish for Columbia University's Oral History Research Office, Pruss said early dirigible travel was safe, and therefore he strongly believed that sabotage was to blame. He stated that on trips to South America, which was a popular destination for German tourists, both airships passed through thunderstorms and were struck by lightning but remained unharmed.

1.1.3  Passenger Destroy the airship as the airship’s crew statement.

1.1.4  Eric Spehl; In 1962, A. A. Hoehling published Who Destroyed the Hindenburg?, where he rejected all theories but sabotage, and named a crew member as the suspect. Eric Spehl, a rigger on the Hindenburg who died in the fire. Ten years later, Michael MacDonald Mooney's book, The Hindenburg, which was based heavily on Hoehling's sabotage hypothesis, also identified Spehl as the saboteur; Spehl involvement: (i) Spehl’s girl friend was a communist; (ii) Spehl is located near the fire source; (iii) Gestapo investigations of Spehl involvement in 1938; (iv) Spehl took foto as igniter; (v) NYPD and FBI Finding on initial fire location in regards to Bomb teat and Spehl unable to reset.

1.1.5  Adolf Hitler: It has even been suggested that Adolf Hitler himself ordered the Hindenburg to be destroyed in retaliation for Eckener's anti-Nazi opinions. Neither the German nor the American investigation endorsed any of the sabotage theories.

1.2        Static Spark Hypothesis:

1.2.1  Hugo Ackner; this is not electric spark but caused by Static Spark. The spark ignited hydrogen on the outer skin. The airship's skin was not constructed in a way that allowed its charge to be distributed evenly throughout the craft. The skin was separated from the duralumin frame by non-conductive ramie cords which had been lightly covered in metal to improve conductivity, but not very effectively, allowing a large difference in potential to form between them.

1.2.2  The Hindenburg passed through a weather front of high humidity and high electrical charge. When the ropes, which were connected to the frame, became wet, they would have grounded the frame but not the skin. This would have caused a sudden potential difference between skin and frame (and the airship itself with the overlying air masses) and would have set off an electrical discharge – a spark. Seeking the quickest way to the ground, the spark would have jumped from the skin onto the metal framework, igniting the leaking hydrogen.

1.2.3  In his 1964 book, LZ-129 Hindenburg, Zeppelin historian Dr. Douglas Robinson points out that although ignition of free hydrogen by static discharge had become a favored hypothesis, no such discharge was seen by any of the witnesses who testified at the official investigation into the accident back in 1937.

1.2.4  Addison Bain; that a spark between inadequately grounded fabric cover segments of the Hindenburg itself started the fire, and that the spark had ignited the "highly flammable" outer skin. The Hindenburg had a cotton skin covered with a finish known as "dope". It is a common term for a plasticized lacquer that provides stiffness, protection, and a lightweight, airtight seal to woven fabrics. In its liquid forms, dope is highly flammable, but the flammability of dry dope depends upon its base constituents, with, for example, butyrate dope being far less flammable than cellulose nitrate. Proponents of this hypothesis claim that when the mooring line touched the ground, a resulting spark could have ignited the dope in the skin

1.3        Lightning Hypothesis:

1.3.1  A. J. Dessler, former director of the Space Science Laboratory at NASA's Marshall Space Flight Center and a critic of the incendiary paint hypothesis (see below), favors a much simpler explanation for the conflagration: lightning. Like many other aircraft, the Hindenburg had been struck by lightning several times. This does not normally ignite a fire in hydrogen-filled airships, because the hydrogen is not mixed with oxygen. However, many fires started when lightning struck airships as they were venting hydrogen as ballast in preparation for landing, which the Hindenburg was doing at the time of the disaster. The vented hydrogen mixes with the air, making it readily combustible.

1.4        Engine Failure Hypothesis

1.4.1  Philadelphia Inquirer:  Based on the interview with Robert Buchanan, a crew manning mooring line. As the airship was approaching the mooring mast, he noted that one of the engines, thrown into reverse for a hard turn, backfired, and a shower of sparks was emitted. After being interviewed by Addison Bain, Buchanan believed that the airship's outer skin was ignited by engine sparks. Another ground crewman, Robert Shaw, saw a blue ring behind the tail fin and had also seen sparks coming out of the engine. Shaw believed that the blue ring he saw was leaking hydrogen which was ignited by the engine sparks.

1.5        Incendiary Paint Hypothesis

1.5.1  Paddison Bain: stating that the doping compound of the airship was the cause of the fire. The hypothesis is limited to the source of ignition and to the flame front propagation, not to the source of most of the burning material, as once the fire started and spread the hydrogen clearly must have burned.

1.5.2  Proponents of this hypothesis point out that the coatings on the fabric contained both iron oxide and aluminum-impregnated cellulose acetate butyrate (CAB).These components remain potentially reactive even after fully setting. In fact, iron oxide and aluminum can be used as components of solid rocket fuel or thermite. For example, the propellant for the Space Shuttle solid rocket booster includes both "aluminum (fuel, 16%), (and) iron oxide (a catalyst, 0.4%)".

1.6        Hydrogen Hypothesis

1.6.1  Offering support for the hypothesis that there was some sort of hydrogen leak prior to the fire is that the airship remained stern-heavy before landing. There are many theories about how that gas might have leaked, but the actual cause remains unknown. Many believe it was that a bracing wire cracked (see below), while others believe that a vent was stuck open and gas leaked through. During one trip to Rio, a gas cell was nearly emptied when a vent was stuck open, and gas had to be transferred from other cells to maintain an even keel.

1.7        Puncture Hypothesis

1.7.1  One hypothesis on how gas could have leaked is that one of the many bracing wires within the airship snapped and punctured at least one of the internal gas cells during one of the sharp turns in the landing maneuver.

1.7.2  Advocates of this hypothesis believe that the hydrogen began to leak approximately five minutes before the fire. Newsreels as well as the account of the landing approach show the Hindenburg made several sharp turns, first towards port and then starboard, just before the accident. Gauges found in the wreckage showed the tension of the wires was much too high, and some of the bracing wires may have even been substandard. One bracing wire tested after the crash broke at a mere 70% of its rated load. A punctured cell would have freed hydrogen into the air and could have been ignited by a static discharge (see above), or it is also possible that the broken bracing wire struck a girder causing sparks to ignite hydrogen

1.8        Structural Failure Hypothesis

1.8.1  Captain Pruss believed that the Hindenburg could withstand tight turns without significant damage. Other engineers and scientists believe that the airship would have been weakened by being repeatedly stressed. The airship's landing approach proceeded in two sharp turns. The first turn was towards port at full speed as the airship circled the landing field. After it had circled the landing field, the wind shifted direction towards the southwest, and a sharper turn to starboard was ordered near the end of the landing maneuver. One or both of these turns in opposite directions could have weakened the structure

1.9        Fuel Leak Hypothesis

1.9.1  The 2001 documentary Hindenburg Disaster: Probable Cause suggested that 16-year-old Bobby Rutan, who claimed that he had smelled "gasoline" when he was standing below the Hindenburg's aft port engine, had detected a diesel fuel leak. During the investigation, Commander Charles Rosendahl dismissed the boy's report. The day before the disaster, a fuel pump had broken during the flight. A crew member said this was fixed but it may not have been done properly. The resulting vapor would have been highly flammable and could have self combusted. The film also suggested that overheating engines may have played a role.

The most conclusive proof against the fabric hypothesis is in the photographs of the actual accident as well as the many airships which were not doped with aluminum powder and still exploded violently: Regardless of the source of ignition or the initial fuel for the fire, there remains the question of what caused the rapid spread of flames along the length of the airship. Here again the debate has centered on the fabric covering of the airship and the hydrogen used for buoyancy.

After the incident occurred, it was determined that the “new & improved” covering the exterior of the aircraft was very flammable. The slightest spark easily could have set the covering ablaze. Most people believed that the air inside the aircraft keeping it aloft was to blame, saying that it was too rich in oxygen; however, this is not the case. It is believed that as the Zeppelin approached Lakehurst, static friction caused a spark that sent the craft crashing to the ground! Since then, all new materials undergo rigorous property testing for strength and ignition point (the point when an object is able to light on fire).

Basic Design Concept on an Airship

Basic Design Concept on an Airship

Some of the earlier scientific and technical documents related to airship design can be found as technical reports from NACA and the Royal Aeronautical Society (RAeS). One of the most famous is a report by Lamb focusing on the study of inertia coefficients of an ellipsoid moving in a fluid: these coefficients were needed to keep into account added masses in airship design. The increased interest in airships of the first years of the 20th century was supported by studies on airship design focusing their attention on aerodynamics and weight which was considered at the moment the two most critical issues in the design of airships. Two reports by Tuckerman, the first dealing with the determination of forces on an airship hull and the second focusing on inertia factors show the need for a precise loads assessment in order to design a lightweight structure able to sustain the stresses due to lifting gas and dynamic pressure. The experience and knowledge in airships gained during the period 1900-1927 by pioneering designers like General Umberto Nobile in Italy, Count Zeppelin and Nikolaus Basenach in Germany, and Goodyear in the USA are reported in a book by Thomas Blakemore and Watters Pagon [4] where all the subsystems of an airship are considered one by one. The approach followed in to solve the weight estimation (which can be considered the most critical in airship design) is based upon comparison with already designed and built airships where a wide list of tables in which the characteristics of a large number of airships are listed. In the same year a book by Charles P. Burgess was edited, in which the approach to size estimation is different: this author proposes a design methodology based on preliminary design calculations, evaluation of static and dynamic bending moments, gas pressure stresses, design of cars for power systems, passengers, and flight crew, gas cells, and finally tail cones, stabilizing surfaces, and mast mooring gears. This book provides one of the first examples of a complete list of formulas to be used for the initial estimation of size and horsepower for a given performance and proposes a well coded “step by step” embodiment process to deploy the entire design process in a systematic way. A resume of the design experiences of the years up to the 1940s can be found in a technical manual in which the formulas and methodologies developed for the design are summarized in a very practical and “design oriented” way.

The Hindenburg accident and the interest towards vehicles with higher speed deadened the interest in airships, and in 1962, the US Navy program for airships stopped. The design process of airships is kept going by Kostantinov who collected the formulas and experiences in the field of airships and merged the up to date aerodynamic and structural research in a comprehensive paper. Since the 1970s, airships and blimps are designed for advertising purposes or touristic adventure trips: Goodyear in USA and Zeppelin in Germany are good examples of such activities. The increase in personal computers and the computational load available made possible the solutions of complex equations and the large number of simulations that can be ran simultaneously, compared to experimental data (as for the studies of CFD related to the German LOTTE). Also the airship design field was affected by these new capabilities: the work of Lutz et al. is one of the fist describing the optimization of the shape of an airship by means of evolutionary algorithms and stochastic methods: the airship design process can make now use of the new available computing capabilities.

Khoury and Gillet present a book in which a chapter is devoted to Design Synthesis. Airship design now focuses its attention on the integration of sub-systems and trade-off considerations. Moreover, the design process is divided in Conceptual, Preliminary and Detailed phases. Flowcharts are presented to drive and support the designer in the Conceptual Design phase, in the trade off analysis, and in the trade study process. The airship is considered as a system, and the mutual interactions between subsystems (condensed in the airship sizing matrix) is considered the key of success for a good and balanced design. Also, sensitivity analysis and parametric weight estimation (derived from the aircraft conceptual methodologies) are introduced in this comprehensive book. In the end of the 20th century, flight simulation is proposed not only for the training of pilots, but also to check the design results and to verify the behavior of the airship, even in the conceptual design phase. The availability of new film materials, efficient solar panels, and the need for high altitude observation platforms focused the attention of designers to High Altitude Platforms (HAP).

In a study by Mueller et al. the design of a HAP is presented in a parametric way: data like weight of the envelope and efficiency of solar panels are not kept fixed. The design process output is not a defined sizing, but a series of graphs which the designer can use to dimension the airship with materials available at the moment. With this method, the design can be updated if new materials or technology become available. Also, in the work of Wei et al. and Nickol et al. the attention is focused on the trade-off analysis, on the sensitivity analysis, and on how the airship would be impacted by a new technology or change in mission requirement. In the latter of these two papers, the design is based upon the proposal of several configurations, each one evaluated in the mission through a Life Cycle Cost Analysis approach where a design is considered good if it presents a cheap operational cost and a low cost for environmental impact and final dismissing.

The work of Yu and Lu presents a flowchart describing the design process for a HAP; moreover, a list of tables shows how the change of design parameters (like the purity of helium, or the sunlight hour related to the season of the year) affect the lift. The most interesting part of this study reports the effects of technology advances on airship performance parameters: by this way the designer can have an idea of how the payload can be increased with an increase in propeller weight/mass ratio and solar cells efficiency, or a decrease of envelope area weight and batteries capacity/mass ratio.

Also, Chen presents a similar work of sensitivity analysis arriving at similar results in terms of influence of weights and efficiency on the design: a design flowchart is presented here also to assure the equilibrium between lift and weight due to solar panels, structure, batteries, and propulsion systems. The multidisciplinary approach to design, which is a consequence of a concurrent engineering approach, has been applied also to airship design: the work of Ram and Pant presents the aerodynamic and structural optimization of an airship using variable thickness fabrics and a low drag shape. As the new reprint of the book Airship Technology reports, in addition to the classical interest related to materials, solar panels, and unconventional configurations, one of the challenges for the future is the design of multi gas, multi chamber airships seems to be a solution for cost reduction and lower environmental impact.

Comparison between an Airship and a Hot Air Balloon

Comparison between an Airship and a Hot Air Balloon

An airship, also known as a dirigible, is a powered lighter-than-air craft. In other words, an airship is an aircraft that derives its lift from a lifting gas (usually helium or hot air) while it is propelled forward by an engine. There are four (4) categories of airships: Rigid, Semi-Rigid, Non-Rigid and Hot Air Airships.

1.1        Rigid Airships

As their name implies, rigid airships have an internal frame. The Zeppelins and the USS Akron and Macon were famous rigid airships. The rigid structure, traditionally an aluminum alloy, holds up the form of the airship. In general rigid airships are only efficient when longer than 120 Meters (360ft.) because a good weight to volume ratio is (or was) only achievable for large airships. For a small airship the solid frame would have been too heavy. There is hope that the use of composite materials will change this.

1.2        Semi-Rigid Airships

Semi-rigid airships were more poplular earlier this century. They usually comprise a rigid lower keel construction and a pressurized envelope above that. The rigid keel can be attached directly to the envelope or hung underneath it. The airships of Brazilian aeronaut Alberto Santos-Dumont were semi-rigids. One of the most famous representants of the type wasItalia, the airship which General Umberto Nobile used on his attempt to reach the North Pole.

1.3        Non-Rigid Airships or Blimps 

Non-rigid airships, also known as Blimps, are the most common form nowadays. They are basically large gas balloons. Their shape is maintained by their internal overpressure. The only solid parts are the passenger car and the tail fins. All the airships currently flying for publicity use are of that type; the Goodyear Blimps, the Budweiser and the Metlife Blimps in the USA, and the Fuji Blimp in Europe.

1.4        Hot Air Airships

Hot air airships, also known as thermal airships, are counted as a fourth kind even though they are technically part of the non-rigid category. Hot air airships are derived from traditional hot air balloons. Early models were almost like balloons with an engine and tail fins added. Pretty soon envelopes were lengthened and the tail-fins and rudder were pressurized by air from the wash of the propeller. Newer hot air airships maintain their shape with internal overpressure in the whole envelope, a feature which older models did not have.



A hot air balloon is powerless, relying on the winds for locomotion, while an airship has a motor, allowing it to drift with its own power. A hot air balloon is just an “envelope” (the balloon part) that is capable of containing hot air, a burner, and a basket. Unlike blimps or dirigibles, hot air balloons do not need specific gases, such as helium, to fly. They operate on the simple principle that hot air is lighter than colder air. However, hot air balloons cannot be steered, and they rely on wind to move them along.

The History of Airships

The History of Airships

The history of airships has its beginnings in the eighteenth century with the first recorded flight of a non-rigid dirigible by Jean-Pierre Blanchard it 1784. The airship consisted of a balloon fitted with a hand powered propeller for propulsion. Attempts at adding propulsion to balloons continued into the nineteenth century with Henri Giffard who was the first person to make an engine powered flight. In 1852, he flew 27 kilometers in a steam powered airship. Twenty years later in 1872, Paul Haenlein flew an airship over Vienna that was powered by an internal combustion engine, the first time such an engine was used to power an aircraft.

In the 1890s Count Ferdinand von Zeppelin began experimenting with rigid airships. This led to the launch of the famous Zeppelins and the “Golden Age of Airships”.

During the first half of the twentieth century airships gained popularity for passenger transport and military uses such as tactical bombing, reconnaissance, surveillance, and communications. During World War I, Germany, France, Italy, and Britain all used airships for various military operations. The Norge, an Italian semi-rigid airship became the first confirmed aircraft to fly over the North Pole. The USS Shenandoah was the first American built rigid airship. It was operated by the United States Navy and first flew in 1923. The Shenandoah was the first airship to fly across North America and was the first dirigible to use helium as a lifting gas.

LZ 129 Hindenburg was a large German commercial passenger-carrying rigid airship, the lead ship of the Hindenburg class, the longest class of flying machine and the largest airship by envelope volume. The airship flew from March 1936 until destroyed by fire 14 months later on May 6, 1937, at the end of the first North American transatlantic journey of its second season of service. In 1937, moments before landing, the Hindenburg, a hydrogen filled rigid airship burst into flames, killing 36 people onboard and becoming one of the most well-known and widely remembered airship disasters of all time.

The public’s confidence in airships was shattered by this disaster. This along with the onset of World War II brought the use of airships for passenger transport to a halt. Airships also saw deployment during the Second World War and were predominantly used by the United States Navy for patrol and convoy escorts for ships to detect enemy U-boats. In the years since the war, airships have seen a decline in popularity and usage. In present day, airships are typically used for advertising, sightseeing, surveillance, and research. A timeline of airship development starting in the 1850s with Henri Giffard’s first engine powered dirigible and ending in the 1960s.

PENGURUSAN PUSAT PEMINDAHAN SEMENTARA BENCANA BANJIR

PENGURUSAN PUSAT PEMINDAHAN SEMENTARA BENCANA BANJIR

1.0   PENDAHULUAN

1.1   Am

Banjir adalah satu bencana alam yang berlaku disebabkan oleh faktor klimatologi atau faktor iklim seperti keadaan suhu, taburan hujan, sejatan, pergerakan angin dan keadaan semulajadi muka bumi. Di Malaysia banjir maupun banjir kilat berlaku secara tradisi, terutama di Pantai Timur Semenanjung semasa musim tengkujuh. Perubahan cuaca yang dipengaruhi oleh Monsun Timur-Laut dan Barat-Daya menyebabkan hujan lebat dan banjir terutamanya di kawasan pantai. Purata hujan tahunan adalah sebanyak 3,000 mm tetapi adalah tidak mustahil jika keamatan hujan akibat rebut boleh melebihi 100mm per jam dan 60 mm dalam masa 24 jam. Kira-kira 29,720 km² atau 9% daripada keluasan Malaysia cenderung untuk dilanda banjir dan ianya mempunyai 4.9 juta atau 21% daripada populasi penduduk Malaysia.

Peningkatan kekerapan berlakunya banjir dalam negara  berlaku secara sama ada semulajadi akibat perubahan monsun ataupun akibat peningkatan kawasan setinggan dalam bandar. Banjir biasanya disebabkan sama ada oleh hujan yang berterusan menyebabkan kuantiti yang lebih besar daripada biasa atau air sungai yang melimpah ke tebing sungai ataupun daripada kedua-duanya sekali. Dasar sungai yang semakin cetek di kawasan hilir akibat daripada banjir yang berulangan berlaku. Keadaan kawasan perbandaran yang didasari oleh tanah liat yang bersifat tidak telap air, cepat tepu dan kurang menyerap air, jika berlaku hujan lebat akan menyebabkan air sungai cepat melimpah ke tebing. Hakisan tebing yang memberikan kesan terhadap ketebalan sedimen dalam sungai juga menyumbang kepada kejadian banjir. Muhd. Barzani Gasim et al. (2007) mengenal pasti banjir yang berlaku di Dungun, Terengganu adalah disebabkan oleh empat faktor: (i) curahan hujan yang tinggi; (ii) aliran sungai yang perlahan; (iii) luruan laut ke arah darat; dan (iv)halaju dan hala tiupan angin ke daratan. Fenomena di atas adalah kesan daripada beza pasang surut yang agak besar di kawasn pantai timur.

1.2   Faktor Penyebab Banjir

Beberapa faktor penyebab yang menyumbang kepada kejadian bencana banjir, antaranya adalah seperti berikut:

(a)                Hujan Berpanjangan / Tanpa Henti

Hujan berterusan dan berpanjangan tanpa henti boleh menyebabkan banjir. Kawasan tadahan hujan terpaksa menerima lebihan kuantiti air yang banyak hasil dari hujan berpanjangan dan akan mengakibatkan banjir berlaku di kawasan sekitarnya.

(b)               Pembangunan Permodenan

Kebelakangan ini, banyak projek pembangunan dijalankan atas dasar pemodenan dan kemajuan sesuatu kawasan. Ekoran itu, ekosistem sesuatu kawasan telah terganggu akibat kerja-kerja pembangunan ini yang melibatkan tarahan bukit, sungai sekitar kawasan pembangunan menjadi sempit dengan mendakan lumpur pembinaan, penebangan pokok-pokok yang menjadi kawasan tadahan hujan. Apabila berlakunya hujan lebat, maka sungai yang sempit tadi tidak dapat menampung kuantiti air yang banyak hasil dari hujan yang turun, dan sekaligus menyumbang kepada berlakunya banjir.

(c)                Hakisan Sungai

Terdapatnya dua (2) faktor utama yang melibatkan hakisan sungai; iaitu (i) hakisan sungai secara semulajadi; dan (ii) hakisan akibat buatan manusia seperti pembungan sampah yang tidak teratur ke dalam sungai. Hakisan pada tebing sungai berlaku perlahan-lahan secara semulajadi akibat hujan lebat ataupun arus yang kuat, dan ia menyebabkan sungai menjadi semakin cetek, dan memungkinkan banjir berlaku.

(d)               Pemusnahan Hutan Simpan

Hutan simpan semulajadi menyumbang kepada penstabilan ekosistem serta penetapan suhu bumi. Melalui hutan, ia membantu dalam menyerap air antara 2% hingga 20% daripada air hujan. Apabila berlakunya pemusnahan hutan yang tidak terancang, ia akan menyebabkan ekosistem hutan tersebut menjadi tidak konsisten. Ini boleh menyebabkan banjir berlaku di kawasan hutan akibat lebihan air yang tidak dapat diserap oleh akar-akar pokok seperti kebiasaanya.

(e)               Kegagalan Perancangan Sistem Perparitan

Perancangan teliti harus dijalankan pada sistem perparitan. Kegagalan merancang boleh mengakibatkan berlakunya banjir samada banjir besar mahupun banjir kilat. Kapasiti aliran air di setiap sistem perparitan haruslah berkadaran terus dengan pembangunan setempat yang dijalankan.

1.3   Kesan Akibat Banjir

Beberapa kesan akibat banjir dapat dilihat yang melibatkan kemusnahan harta benda, kecelaruan sosial, kematian hidupan serta banyak lagi. Antara kesan negatif banjir adalah seperti berikut:

(a)                Kemusnahan Tanaman Pertanian

Tanaman pertanian musnah akibat banjir yang melanda di kawasan pertanian. Ia mengakibatkan kerugian besar kepada petani serta kesan terus kepada pengguna akibat kekurangan bekalan makanan.

(b)               Wabak Penyakit

Ekoran banjir yang melanda, kesan paling ditakuti adalah wabak penyakit yang mungkin disebabkan oleh banjir seperti penyakit taun, malaria serta penyakit berjangkit lain.

(c)                Kemusnahan Harta Benda

Sudah pastinya kemusnahan harta benda akibat banjir yang melanda boleh mengakibatkan tekanan hidup kepada mangsa apabila kehilangan harta benda seperti rumah, pakaian, kenderaan, aset dan banyak lagi.

(d)               Kematian

Kesan yang paling menyayat hati apabila adanya berlaku kehilangan nyawa akibat banjir. Kebiasaanya ianya boleh berlaku jika ciri-ciri keselamatan semasa banjir tidak diendahkan seperti bermain di kawasan banjir yang mungkin kawasan tersebut ditutupi air yang dalam atau akibat benda sekeliling yang boleh mendatangkan kecederaan dan sekaligus menyebabkan kematian.

  

(e)               Kerugian kepada Kerajaan dan Orang Awam

Banjir menyebabkan kerosakan harta awam seperti jalan raya, jambatan, bangunan kerajaan, sistem telekomunikasi dan sebagainya. Kemusnahan ini mengakibatkan kerajaan terpaksa menanggung kos baik pulih aset mahupun peralatan yang rosak.

1.4   Persediaan Awal Sebelum Bencana

Melalui kajian yang dibuat mahupun sejarah lampau sesuatu kawasan berisiko berkaitan potensi mengalami banjir, pemantauan dan pendokumentasian dibuat berdasarkan jenis bencana dan bersedia membangunkan infrastruktur Sistem Amaran Awal Bencana di tempat tersebut. Melalui maklumat tersebut, perancangan pemantapan keupayaan dari segi sumber tenaga dan peralatan dibangunkan dengan lebih sistematik. Pendedahan Sistem Amaran Awal Bencana kepada penduduk sekitar perlu dijalankan dengan kekerapan yang tinggi bagi meningkatkan kesedaran terhadap ancaman yang bakal dihadapi. Atas inisiatif Pegawai Pertahanan Awam Daerah (PPAD) di beberapa Daerah di Johor telah menubuhkan Skuad Pemantau JPAM bagi menilai keadaan semasa paras air dan memberi maklumat awal serta hebahan untuk evakuasi (jika perlu) kepada penduduk setempat melalui rondaan yang dibuat.

Mengenalpasti pusat-pusat pemindahan banjir dengan lebih awal lagi bagi memudahkan urusan evakuasi.  Antara lokasi strategik pemilihan pusat pemindahan banjir adalah seperti Dewan Orang Ramai, sekolah, balairaya, masjid dan lain-lain tempat yang difikirkan selamat untuk menempatkan mangsa banjir. Pemilihan lokasi pusat pemindahan ini perlulah bebas dari sebarang ancaman bencana lain dan selamat. Sekiranya bangunan-bangunan yang telah dikenalpasti itu adalah milik persendirian atau di bawah tanggungjawab agensi lain, maka kebenaran terlebih dahulu perlu diperolehi.  Di antara kriteria dan panduan bagi pemilihan pusat pemindahan adalah seperti berikut:

(a)                Bangunan mempunyai ruangan yang mencukupi dan selamat untuk digunakan;

(b)               Mempunyai kemudahan dan keperluan asas seperti  bekalan air, bekalan elektrik, tandas dan sebagainya; dan

(c)                Lokasi/kedudukannya selamat dari dilanda banjir dan tidak terputus perhubungan.

Persiapan ke arah penyediaan bantuan logistik dan kebajikan dibuat lebih awal lagi.  Bagi kawasan-kawasan yang pada bila-bila masa sering mengalami banjir kilat dan ribut, tahap persediaan sentiasa kemaskini dan dalam status siapsiaga. Bagi kawasan-kawasan yang sering dilanda banjir, kemudahan pangkalan hadapan sebagai tempat penyimpanan bekalan makanan adalah diperlukan.  Tujuannya ialah supaya bantuan makanan dapat diperolehi dengan kadar segera.  Kemudahan seperti ini juga diperlukan bagi kawasan-kawasan yang sering terputus perhubungan.  Jenis makanan asas yang sesuai ialah seperti beras, minyak, teh, kopi, garam, gula, tepung, ikan masin, susu kanak-kanak, biskut, sardin dan lain-lain makanan kering. Perancangan dan mengenalpasti lebih awal  sumber-sumber bekalan makanan  untuk pusat pemindahan, seperti menentukan jenis-jenis bekalan dan pusat bekalan seperti kedai-kedai, pemborong atau lain-lain sumber, dan juga menentukan tempoh sah kegunaan sesuatu bekalan makanan yang mudah rosak dan sebagainya. Jumlah makanan yang disediakan bergantung kepada jumlah   penduduk.    Walau   bagaimanapun, makanan yang disediakan hendaklah boleh menampung keperluan sekurang-kurangnya untuk 7 hari.  Dalam pada itu, tempoh input kegunaan barang-barang ini hendaklah sentiasa diawasi supaya tidak melebihi  tarikh yang ditetapkan.

Kenderaan dan bot-bot penyelamat hendaklah ditempatkan lebih awal di kawasan yang mudah dilanda banjir bagi mengelakkan sebarang masalah sekiranya jalan raya ditenggelami air dan tidak boleh dilalui.  JPAM bersama agensi-agensi penyelamat lain diletakkan dalam keadaan bersiapsiaga menghadapi sebarang kemungkinan bencana banjir. JPAM sentiasa memastikan semua peralatan menyelamat dan kenderaan berada dalam kondisi terbaik dan boleh digunakan bila-bila masa diperlukan. Kelengkapan menyelelamat ini perlulah dilengkapi dengan lain-lain peralatan seperti jaket keselamatan, pendayung, lampu suluh, lampu limpah, tali, pelampung, khemah, generator dan lain-lain peralatan yang difikirkan perlu dalam operasi menyelamat.

Perancangan awal bagi gerak kerja pegawai dan anggota JPAM dilakukan lebih awal dengan susun atur penugasan mengikut keutamaan. Memastikan senarai nama pegawai dan anggota berserta alamat dan nombor telefon sentiasa dikemaskini bagi membolehkan panggilan bertugas dan kerahan tenaga dapat dilakukan bila diperlukan. Semua ini menjadi tanggungjawab PPAD bagi setiap Daerah.

Sebagai langkah pencegahan, beberapa agensi kerajaan yang bertanggungjawab terhadap sistem perparitan dan saliran, perlu mempastikan semua sistem saliran air dibersihkan daripada sampah sarap  terutamanya  sistem saliran di bandar-bandar.  Pengaliran air yang sempurna dapat mengurangkan potensi berlakunya banjir. Papan tanda amaran banjir juga perlu diletakkan di kawasan dan jalan-jalan yang sering dilanda banjir untuk panduan orang ramai.

Program kesedaran dan kependidikan awam hendaklah dilaksanakan secara berterusan dan holistic bagi meningkatkan tahap kesiapsiagaan masyarakat mengahadapi bencana banjir. Latih amal pengurusan dan pengendalian bencana yang melibatkan semua agensi terlibat hendaklah diadakan secara berterusan bagi meningkatkan kompetensi setiap anggota agensi melalui pelarasan yang dibuat oleh pihak Majlis Keselamatan Negara (MKN).