ME 431 TRANSPORT TECHNOLOGY CHAPTER 2. TRANSPORTATION SYSTEMS

1. ME 431 TRANSPORT TECHNOLOGY CHAPTER 2. TRANSPORTATION SYSTEMS

2. 2.1.2 ROAD TRANSPORT ROAD TRANSPORT USES WHEELED VEHICLES ON NATURAL OR IMPROVED SOIL. The natural soil may be improved by: • smoothing and grading the surface; • draining to prevent damage by water; • providing durable surfaces by laying gravel, crushed rock, reinforced concrete or blocks of stone or wood; • sealing surfaces with bituminous materials to prevent erosion by water and to act as a palliative for dust; and • providing bridges, culverts or tunnels to overcome natural obstructions.

3. Roads are classified based on the use as: • Streets or local roads-those primarily for immediate access to residential, business or other premises, farms and other places where there are human activities. • Arterial roads-those between cities and towns or connecting industrial areas thereto. • Expressways or freeways-arterial roads intended to permit continuous and fast movement and with limited access from the sides. • Parkways-those traversing parklands or reservations and intended for non-commercial traffic only.

4. VEHICLES AND POWER THE VEHICLES USED IN ROAD TRANSPORT INCLUDE THOSE: • SOME DRAWN BY ANIMALS(PARTICULARLY HORSES), • SOME DRAWN OR PROPELLED BY PEOPLE (RICKSHAWS AND CYCLES) AND • SOME PROPELED BY ELECTRIC MOTORS DRAWING POWER FROM BATTERIES. • SOME PROPELLED BY FUEL ENGINES IT WILL, HOWEVER, BE DESIRABLE TO RESTRICT THIS SURVEY TO THOSE WHICH ARE PROPELLED BY INTERNAL COMBUSTION ENGINES WHICH MAY BE SPARK IGNITION OR COMPRESSION IGNITION. THE MOST COMMONLY USED FUELS ARE PETROLEUM PRODUCTS SUCH AS PETROL (GASOLINE), KEROSENE AND SOME HEAVIER DISTILLATES.

5. Road vehicles vary in construction according to purpose-the carriage of goods or people, or both.

6. Passenger-carrying vehicles range from a capacity of one person or a few persons to about 50, but the dimensions are the main factors because people require floor and air space rather than actual mass carrying capacity. Passenger vehicles may be divided broadly into two classes: - • Motor cars-powered vehicles designed to carry less than ten people. • Motor buses or coaches-powered vehicles, or combination of tractor and semi-trailer, designed to carry ten or more people

7. Goods-carrying vehicles are designed according to the kind and quantity of goods to be carried and the appropriate methods of loading, unloading and protecting the goods The units and combinations cover the full range shown in figure of next slide, and a powered vehicle is usually referred to as a truck.

9. The units and combinations shown are as under: • A. Single vehicle containing the engine and carrying body. Usually has two wheel axles but, in some instances, may have three or four axles. • B. Tractor containing the engine only. This is used for hauling un-powered vehicles and may have two, three, or four axles. • C. Full trailer-non-powered vehicle carrying the whole of its own mass and that of the load may have two or more axles. • D. Semi-trailer-an un-powered vehicle having axles at rear end only and requiring support by a tractor at the front end. May have one, two or more axles. • E. Train consisting of dual-purpose vehicle (A) and full trailer (C) - • F. Train consisting of tractor (B) and full trailer (C). • G. Tractor (B) and semi-trailer (D) coupled to form a single operating unit. • H. Train consisting of tractor (B), semi-trailer (D) and full trailer (C).

10. TERMINALS IN THE MOVEMENT OF PEOPLE , TERMINALS ARE PLACES OF ASSEMBLY, DISCHARGE OR TRANSFER PASSENGERS AT A LIMITED NUMBER OF POINTS ON A ROUTE. THE SIZE AND CHARACTER OF THE FACILITIES AT THESE POINTS DEPEND LARGELY ON THE VOLUME OF TRAFFIC AND FREQUENCY OF SERVICES. GOODS TERMINALS REQUIRE FACILITIES FOR ACCUMULATION OF OUTGOING CONSIGNMENTS PENDING FURTHER TRANSPORT TO CONSIGNEES. THE FACİLİTİES MAY İNCLUDE PLATFORMS AND HANDLİNG AND LİFTİNG APPLİANCES TO MATCH THE KİNDS AND VOLUME OF GOODS PASSİNG THROUGH THE TERMİNAL.

11. SUSCEBTIBILITY TO INCLEMENT WEATHER ROAD TRANSPORT CAN BE AFFECTED BY RAIN, FLOOD,STORM, SNOW, ICE AND FOG WHICH MAY RENDER ROADS IMPASSABLE. IN DESERT, IN TROPICAL COUNTRIES AND OTHER HOT AREAS HEAT MAY VAPORIZE SOME LIQUID FUELS SUCH AS THE LIGHTER DISTILLATES FROM PETROLEUM. HEAT MAY ALSO UNDULY EXPAND THE AİR İN PNEUMATİC TYRES AND LEAD TO THEİR DESTRUCTİON. ROADS ARE SUSCEPTİBLE TO DAMAGE BY RAİN, FLOOD, İCE AND SNOW.

12. CAPACITY THE CARRIYING CAPACITY OF PASSENGER VEHICLES IS DETERMINED BY FLOOR SPACE AVAILABLE, AND THIS IS INCREASED IN SOME INSTANCES BY HAVING TWO DECKS. THE CARRYİNG CAPACİTY OF GOODS-CARRYİNG VEHİCLES İS LİMİTED BY- • the total mass which may be imposed on the floor of the carrying body; and • the volume of the space within a fully-enclosed body, or withinthe height, width and length of load, permitted by law.

13. THE RELATIONSHIP OF STOWAGE SPACE TO MASS-CARRYING CAPACITY VARIES WITH THE SIZE OF VEHICLES AND ANY SPECIAL EQUIPMENT ATTACHED. BUT, IN GENERAL , BOTH CAPACITIES ARE FULLY ABSORBED WHEN THE GOODS LOADED HAVE A DENSITY OF 320 TO 480 KILOGRAMS PER CUBIC METRE. RAILWAY VEHICLES, ON THE OTHER HAND, ARE FULLY LOADED WITH GOODS HAVING A DENSITY OF 400 TO 560 KILOGRAMS PER CUBIC METRE.

14. 2.2 WATER TRANSPORT THE VEHICLES USED IN WATER TRANSPORT MAY BE DESCRIBED FORMALLY AS HOLLOW VESSELS OR HULLS WHICH ARE MADE TO MOVE THROUGH OR ON WATER UNDER SOME NATURAL OR MECHANICAL POWER. THESE VESSELS HAVE PARTICULAR NAMES DEPENDING UPON THEIR SIZE, CONSTRUCTION,POWER AND PURPOSE BUT, AS A CLASS, SMALL VESSELSS ARE OFTEN TERMED “BOATS” AND LARGER VESSELS “SHIPS”.

15. Power • Apart from manpower, the power to move vessels may be derived from external or internal sources:- • (a) External sources-wind, animals, land vehicles (only to tow unpowered vessels along canals and narrow streams). • (b) Internal sources-steamengines, steam turbines and internal combustion engines of gasoline and diesel.

16. VESSELS OTHER THAN THOSE DESIGNED AND ARMED FOR USE IN WAR, VESSELS MAY BE CLASSIFIED AS- • THOSE OF SMALL SIZE AND USED FOR PRIVATE PLEASURE AND SPORT-YACHTS, ROWING BOATS AND MOTOR BOATS, • THOSE USED IN TRADE AND COMMERCE FOR THE TRANSPORT OF PEOPLE AND/OR GOODS-MERCAHNTS VESSELS,AND • THOSE USED FOR ANCILLARY OR SPECIAL PURPOSES-PATROL VESSELS TO ASSIST IN LAW ENFORCEMENT, FISHING VESSELS.

17. TERMINALS WATER MOVEMENTS BEGIN AND END AT LAND POINTS(PORTS) AND THE FACILITIES CONNECTING VESSELS TO LAND SERVICES ARE THE TERMINALS. THE NECESSITIES IN WATER TRANSPORT TERMINALS ARE- • LOCATION AS NEAR AS POSSIBLE TO THE POINTS OF ORIGIN AND DESTINATION OF PASSENGERS AND GOODS • SHELTER OF THE VESSELS FROM INCLEMENT WEATHER WHILS AT THE TERMINAL • SUFFICIENT DEPTH OF WATER TO ENABLE VESSELS TO REMAIN AFLOAT AT ALL CONDITIONS OF TIDE, • FACILITIES FOR THE EASY TRANSFER OF PASSENGERS AND GOODS TO AND FROM VESSELS.

18. In the case of bulk transport of liquid cargoes in tankers, the transfer of the cargo may be undertaken at a mooring away from the shore, by use of an underwater pipeline to connect the vessel to the shore depot. • IN SOME INSTANCES, THE PREMISES OF INDUSTRIAL AND COMMERCIAL UNDERTAKINGS ARE NEXT TO NAVIGABLE WATERS AND THERE IS OPPORTUNITY FOR MORE DIRECT TRANSFER OF GOODS AS IN THE CASE OF İSKENDERUN DEMİRÇELİK and EKİNCİLER in İSKENDERUN. Susceptibility to Inclement Weather The operation of water transport services can be adversely affected by ice, snow, fog, wind and lightning. Conditions can be severe and endanger the vessel and all that it carries.

19. CAPACITY THE SPACE -MASS CAPACITY IN WATER TRANSPORT HAS A SPECIAL ASPECT IN THAT IT IS DESIRABLE FOR A VESSEL TO BE LOADED SO THAT HOLDING CAPACITY IN VOLUME IS NOT ONLY FULL,BUT THAT THE MASS IS SUFFICIENT TO FORCE THE VESSEL DOWN IN THE WATER TO , BUT NOT BEYOND, THE APPROPRIATE LOAD-LINE THE SPACE-MASS CAPACITY VARIES FROM VESSEL TO VESSEL WITHIN A RANGE FROM ABOUT 600 TO 700 KILOGRAMS PER CUBIC METRE ,AND IS THEREFORE GREATER THAN NORMALLY ACCEPTED IN RAILWAY TRANSPORT( 400 KG/CUBIC METER)

20. SPEED THE SPEED AT WHICH VESSELS TRAVEL IS MEASURED IN KNOTS, AND A KNOT IS ONE NAUTICAL MILE PER HOUR. A NAUTICAL MILE IS ONE MINUTE OF ARC OF A GREAT CIRCLE OF THE EARTH AND, FOR CONVENIENCE, IS AVEREGED AT 2000 METRES. The possible and desirable speeds are dependent upon the following factors:- • the resistance offered by water to the hull, the shape of which is relevant; • the resistance offered by still air to that part of the hull above water; • the power of the engines measured according to the thrust exerted on the water by the propellers, the design of propeller being a factor; • the direction and force of currents of water or air in which the vessel is moving; • the smoothness or otherwise of the surface of the water; and • the degree of vibration and noise involved, affecting comfort of passengers and the condition of the vessel and its cargo. In general, travelling speeds range from 10 to 30 knots for cargo vessels and 20 to 40 knots for passenger vessels of the conventional kind.

21. OTHER MEANS OF WATER TRANSPORT A NEW AND UNCONVENTIONAL VESSEL IS THE HYDROFOIL THE HULL OF HYDROFOIL, WHEN PROPELLED, IS LIFTED, CLEAR OF THE WATER BY THE ACTION OF UNDERWATER WINGS AND LEGS ATTACHED TO THE HULL. VESSELS OF THIS TYPE ARE CAPABLE OF HIGH SPEEDS BUT, SO FAR, ARE OF SMALL SIZE AND USED FOR THE CARRIAGE OF PEOPLE FOR SHORT DISTANCES ON SHELTERED WATERS

22. HYDROFOILS ARE ABLE TO PROVIDE HIGH-SPEED MARINE TRANSPORTATION. A HYDROFOIL HAS WINGS OR FOILS DESIGNED TO LIFT A HULL BODILY OUT OF WATER. IT USES THE PRINCIPLE SUCH THAT SMALL SURFACES MOVING QUICKLY THROUGH THE WATER PRODUCE LIFT. THIS CAN BE USED TO RAISE THE MAIN PART OF A VESSEL ABOVE THE SURFACE OF THE WATER. WHEN THEY ARE TRAVELLING AT SPEED, THEY RISE OUT OF THE WATER ON LEGS.

23. HOVERCRAFT (THE AIR CUSHION VEHICLE) IS ANOTHER UNCONVENTIONAL VEHICLE AND CAN TRAVEL OVER LAND OR WATER. HOVERCRAFT IS ONLY SUITABLE FOR CARRYING LOW – DENSITY LOADS (PASSENGERS AND CARS)

24. HOVERCRAFT BELONGS TO THE CATEGORY OF WHAT CAN BE DESCRIBED AS ”AIR CUSHION VEHICLES” OR “ GROUND EFFECT VEHICLES”. IN PRINCIPLE, A HOVERCRAFT COMPRISES A BODY OR HULL IN WHICH A ROTOR (LIFT PAN ) IS SO MOUNTED THAT IT CAN PRODUCE AN AIR CUSHION ON WHICH THE CRAFT ISSUPPORTED.

26. Compressed air skirt plate Air gap Ground or water surface WORKING PRINCIPLE OF HOVERCRAFT Jets of compressed air lift the hovercraft off the ground, and flexible skirts around the craft retain the air cushion, and help to keep it stable. The air cushion reduces friction between the craft and earth's surface. It also acts as a spring suspension to reduce some of the vertical acceleration effects.

27. HOW A HOVERCRAFT OPERATES? A hovercraft operates above the surface of water or land. The vehicle is supported on a cushion of air 1.2 to 2.4 m (4 to 8 ft) thick. The air cushion is provided by a large fan that pushes air downward within a flexible skirt attached to the perimeter of the vehicle. The skirt maintains the cushion by restraining the air. It makes the vehicle appear to be operating only a few inches (5-20cm) above the surface.

28. Different designs of air compression systems for hovercrafts

29. THE TYPES AND USES OF HOVERCRAFTS? There are three basic types of hovercraft now being developed. They may be described as: I. Amphibious hovercraft (IT CAN OPERATE OVER WATER , ICE, SMALL ROCK –AND LAND)  II. Non-amphibious hovercraft (RESTRICTED TO OVER WATER OPERATION ONLY)  III. Semi-amphibious hovercraft(RESTRICTED TO OVER WATER OPERATION BUT LOADING AND UNLOADING CAN BE DONE ON DRY LAND)

30. ROLL-ON/ROLL-OFF (RO-RO) SHIPS The Ro-Ro, or more fully the Roll on - roll off vessel, comes in a number of shapes and sizes, but generally in two types; the passenger ro-ro and the Cargo ro-ro.Passenger ro-ros have become common sights wherever people want to travel over water with their vehicles. It is probably the only type of cargo vessel that most people have travelled on. Usually a rear door (but sometimes a bow door) allows for vehicles to be driven on and off, stored on the car deck below the passenger accommodation areas. The cargo ro-ro is less "plush" than the passenger type, as these vessels are designed for the carriage of commercial vehicles where luxurious passenger accommodation is not a primary consideration. Considerable concerns have been expressed over the bow-door type of ro-ro design

31. Stabilityrefers to the ability of a vessel to withstand high winds and seas and resist capsizing by returning to an upright position after being heeled over. Many forces influence the stability of a vessel in the water and each type of vessel reacts differently to heeling forces. Operators should be aware of how the design and loading of their boat interact with external forces of nature and affect their boat’s stability. A properly designed and loaded boat should resist heeling forces when operated within its environmental limits

32. Adding weight above a boat’s centre of gravity will change its stability. If the centre of gravity is raised too much, the boat will become unstable. As a result, less tilt is required to capsize the vessel (see Figure Added Load). • Removal of weight from below the centre of gravity also decreases stability.  

33. 2.3 AIR TRANSPORT THE ATMOSPHERE CAN BE DIVIDED ARBITRARILY INTO TWO LAYERS WHICH ARE TERMED THE TROPOSPHERE AND STRATOSPHERE RESPECTIVELY. THE IMAGINARY BOUNDARY BETWEEN THE TWO IS REFERRED TO AS THE TROPOPAUS. THE TROPOSPHERE EXTENDS FROM THE EARTH’S SURFACE TO A HEIGHT OF ABOUT ELEVEN KILOMETRES AND CONTAINS ABOUT THREE-QUARTERS OF THE AIR MEASURED BY MASS. THE STRATOSPHERE IS THE REGION ABOVE THE TROPOSPHERE AND IS CHARACTERIZED BY FREEDOM FROM CLOUDS, SNOW, ICE AND STORM, AND BY A CONSTANT TEMPERATURE. HOWEVER, AT THIS HIGH ALTITUDE ARE FOUND SOME RAPIDLY FLOWING STREAMSOF AIR (JET-STREAMS) WHICH MAY PRODUCE SOME TURBULENCE.

34. AEROPLANES CAN BE CALASSIFIED AS- • LAND PLANES-THOSE WHICH ARE FITTED WITH WHEELS OR SKIDS FOR TRAVERSING THE GROUND, • SEA PLANES OR FLYING BOATS –THOSE WHICH ARE EUIPPED WITH FLOATS OR A BODY CAPABLE OF SUPPORTING THE MACHINE ON WATER; AND • AMPHIBIAN PLANES- THOSE WHICH COMBINE THE PECULIAR FEATURES OF BOTH LAND AND SEA PLANES AND THEREFORE ARE CABABLE OF TAKING OFF AND ALIGTHING ON BOTH LAND AND WATER.

35. AIRCRAFT AND POWER NAVIGABLE AIRCRAFT WHICH DEPEND FOR LIFT ON THE • DISPLACEMENT OF THE AIR BY HEATED AIR (BALLONS) • LIGHTER GASES (HYDROGEN OR OTHER GASES LIGHTER THAN AIR USED IN ZEPLIN OR OTHER AIR VEHICLES) PLAY NO PART IN THE MODERN AIR TRANSPORT SYSTEM. Dependence is entirely upon heavier-than-air aircraft of three types- • aeroplanes which have their mass supported in flight by fixed wings or "planes"; • helicopters which obtain lift from one or more sets of wings or blades rotating horizontally; and, • hovercraft or air-cushion vehicles which obtain lift from a cushion of compressed air.

36. AN AIRPLANE HAS THREE MAIN PARTS:FUSELAGE (BODY),WINGS AND ENGINE TWO PARTS OF THE WING ARE: AILERON: ITS PURPOSE IS TO CONTROLIZE THE AIRPLANE IN ROLL BY CREATING UNEQUAL OR OPPOSING LIFTING FORCES ON THE OPPOSITE SIDES OF THE AIR PLANES. FLAP: A HINGED OR SLIDING PART OF THE AIRFOIL.IT IS EXTENDED OR DEFLECTED TO INCREASE THE LIFT AND/OR DRAG GENERALLY USED TAKE-OFF OR LANDING. .

37. Low pressure region (longer path-higher velocity) Drag force Air stream lines Angle of attack High pressure region (shorter path-lower velocity) • Greater lift could be obtained from a wing having a cambered shape illustrated in figure below. • As the aircraft is propelled, the air meeting the leading edge of the wing is divided smoothly into two streams. The stream passing over the wing is accelerated with a consequent reduction in pressure on the top. The stream passing below is deflected down­wards with a consequent increase in pressure on the underside of the wing. • About two-thirds of the total lift may come from the reducedpressure on the top of the wing

38. PROPULSION IN AEROPLANES IS PROVIDED BY- INTERNAL COMBUSTION PISTON ENGINES OR GAS TURBINES DRIVING AIR PROPELLERS; OR GAS JETS USING THE REACTION OF HOT GASES OF HIGH VELOCITY TO NOZLES DIRECTED BACKWARDLY

39. Weight Lift Thrust Drag Four forces acting on an airplane are: • weight (W) of the airplane -downwards • lift (L) is the resulting pushing up force against the weight of the body due to the special shape of the wing or airfoil and the relative speed of the wind or air • thrust (T) is the force pushes the body of the plane forward and developed by the engine of the plane • drag (D) is the resistance force to flight or movement due to friction between body and the air itself In a straight and level flight the lift and weight must be equal (L=W) When an airplane is flying at constant speed (zero acceleration) thrust must be equal to the drag (T=D)

40. HELICOPTERS obtaın lıft from the rotatıon of long and slender wıngs or blades, and propulsıon by tıltıng the aırcraft ın a forward dırectıon.

41. WORKING PRINCIPLE OF HELICOPTER

42. In helicopters there are four forces again (Weight, Thrust, Lift and Drag). • In hovering position both thrust and lift (T&L) are upwards while weight and the drag (W&D) due to air flowing downwards over the body are downwards. So sum of T&L is equal to sum of W&D • When hovering T+L=W+D • When ascending T+L>W+D • When descending T+L<W+D

43. THE POWER IS PROVIDED BY ANY OF THE ENGINES USED IN AEROPLANES, BUT WHERE PURE JET ENGINES ARE EMPLOYED THE JET NOZZLES MAY BE PLACED AT THE TİPS OF THE BLADES. THE HELICOPTER IS ABLE TO RISE AND DESCEND VERTICALLY, HOVER IN ONE POSITION, AND MOVE FORWARD WHEN WHENEVER REQUIRED. IN ADDITION THERE IS AN ABILITY TO GLIDE TO A SAFE LANDING IN THE EVENT OF POWER FAILURE. • COMPARED WITH THE CONVETIONAL AEROPLANE ,HOWEVER , THE HELICOPTER HAS DISADVANTAGES: • THE CARRIYING CAPACITY IS MUCH BELOW THAT WHICH IS POSSIBLE IN AEROPLANES AS IT DEPENDS ON THE SIZE AND NUMBER OF THE BLADES. • SPEED IS MUCH LESS BECAUSE THE ROTOR OR ROTORS MUST BE USED FOR BOTH LIFT AND PROPULSION. • THE FLYING RANGE WITHOUT RE-FUELLING IS SMALL.

44. * HELICOPTERS ARE USED COMMERCIALLY FOR – • EXPLOTARY AND RESCUE WORK FOR WHICH OTHER FORMS OF TRANSPORT UNSUITABLE; • RAPID TRASNPORT OF MAIL AND PASSENGERS BETWEEN AIRPORTS AND CITY CENTERS; AND • LIFTING AND PLACING STRUCTURES IN HIGH POSTIONS BEYOND THE REACH OF CRANES AND OTHER LITIING DEVICES.

45. HELICOPTER + AEROPLANE = HELIPLANE IS AN AIRCRAFT THAT CAN TAKE OFF AND LAND LIKE A HELICOPTER AND, WHEN AIRBORNE, CONVERT TO A TURBOPROP AIRPLANE.

46. . • WHEN THE ENGINES ARE VERTICAL, THE TILTROTOR AIRCRAFT OIPERATES LIKE A HELICOPTER. THE ROTORS PROVIDE LIFT AND CONTROL • AS THE ENGINES ARE TILTED DOWNWARD, THE TILTROTOR AIRCRAFT ACCELERATES. THE WINGS GENERATE LIFT AS SPEED INCREASES. CONTROL IS ACHIEVED VIA THE ROTORS AND CONVENTIONAL AERODYNAMIC SURFACES. 3. WHEN THE ENGINES ARE HORIZONTAL, THE TILTROTOR OPERATES AS A CONVENTIONAL TURBOPROP AIRPLANE. LIFT IS PROVIDED BY THE WINGS AND CONTROL IS PROVIDED BY CONVENTIONAL AIRPLANE CONTROL SURFACES.

47. Landing Grounds All except direct-lift machines (helicopters) have a common feature in that the aircraft must travel along the surface of the earth for some distance to gain the speed at which the machine can become airborne, and similarly for the purpose of bringing the machine to rest after alighting. • The runway or flight strip should have the following qualities: - • The area should be level and clear of any obstructions, including adjacent hills, buildings, trees, overhead wires at least to the extent that will permit the aircraft to ascend and descend at a comparatively low angle • Wherever possible, the site should be free of fog, smoke and winds of high velocity. • The area should be reserved for use exclusively by aircraft. • The runways should be outlined by lights to facilitate use at night or when visibility is lessened by fog.