Lecture 3 Road Transport Ielearning.kocw.net/contents4/document/lec/2013/Chungang/Sallyma… ·...
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Lecture 3-
Road Transport I
Section 1 Vehicle Types
Section 2 Technical Aspects
ROAD TRANSPORT ILECTURE STRUCTURE
VEHICLE TYPESMOVEMENT OF GOODS BY ROAD
Many types of vehiclesSuited to all types of cargoCarry small volumes / weights
Compared to rail or inland waterwaysDoor-to-door service
Cargo transported from origin to destination Driver accompanied
Highly competitive
VEHICLE TYPESKEY CHARACTERISTICS
Dominates inland freight movements> 90% inland goods value $$$$> 80% inland freight volume> 6,000 billion tonne-kilometres per year in the EU,USA, CIS, China and Japan
Majority over short distance85% carried <150 km<1% is carried over 1,000 km
Road freight volumes continue to increase
VEHICLE TYPESIMPORTANCE OF ROAD TRANSPORT
Motor vehicleMechanically propelled (has an engine)Used on roadsCarries freight and / or passengers
Goods vehicleOnly carries freight
SynonymsTruckLorryHaulage vehicle
VEHICLE TYPESDEFINITIONS
Propulsion unitEngineCab
Type depends onWeight of cargo to be carriedDistance to be travelled
VEHICLE TYPESROAD TRACTOR UNITS
Cargo carrying unitHighly flexible
Easily coupled and uncoupled from tractor unitsEasily moved by shunters
Two typesDraw-bar trailer
Supports weight of cargo on its wheels when uncoupledSemi-trailer
Legs support the weight when not coupled to the tractor unit
VEHICLE TYPESROAD TRAILERS
Draw-bar Trailer Semi-trailer
Rigid vehicleSingle unit
Tractor and trailer units combinedCannot be uncoupled
Articulated vehicleTractor and trailer are separate unitsTractor and trailer may be coupled and uncoupled
VEHICLE TYPESRIGID & ARTICULATED VEHICLES
Rigid Vehicle
Tractor Trailer
Articulated Vehicle
VEHICLE TYPESGOODS VEHICLE TYPES
Van Flat Bed Box Body
Specialist
Road TrainHeavy LiftWide Load
Curtain Sided
Tanker
Tipper
Low Loader
Rigid formCharacteristics
Highly flexibleCarry 1-3 tonnesOften based on car design
ApplicationsCourier businessMail distributionHome deliveries
VEHICLE TYPESSMALL VANS
Rigid or articulated formDesigned with a platform on which goods are carried
May have drop sides to secure loads Flexible and can accommodate oversized loadsCargo must be secured
RopesTwist locks
Cargo may require covering for protectionSheeting
VEHICLE TYPESFLAT BED
Rigid or articulated formCargo carrying area is enclosed
Protects cargo from weatherProvides good cargo security
Access from rear of vehicle
VEHICLE TYPESBOX BODY
Carry temperature-sensitive loadsChilled or frozen products
Made of insulated material with a refrigerator unit attached May be designed with one or more temperature compartments (zones)
PowerMain engineSeparate engine (genset)
TECHNICAL ASPECTSBOX BODY – TEMPERATURE CONTROLLED
Fibreglass-reinforced plastic (FRP)Advantages
Strong and cheaperDisadvantage
Relatively heavy
AluminiumAdvantages
Light &Easy to repair
DisadvantagesExpensiveNot robust for heavy loads
VEHICLE TYPESBOX BODY - CONSTRUCTION
Articulated or rigidFixed roofed frame with a flexible curtain (tarpaulin)
Curtain fixed to both sides of the frameSecured with straps
Provides easy access for efficient loading and unloading
VEHICLE TYPESCURTAIN SIDED
Less secure than box (rigid) bodied vehiclesSusceptible to damage
TearingIn high winds tarpaulin left open to reduce wind impact
VEHICLE TYPESCURTAIN SIDED
Rigid vehiclesTypically smaller vehiclesEasy to drive in confined / congested areas
Articulated vehicle (tractor + trailer)More manoeuvrableTend to be larger Greater load capacity / length
Better ratio between tare and cargo weightsTractor can leave trailer to be (un)loaded
VEHICLE TYPESARTICULATED VS RIGID VEHICLE
Tare Weight – the weight of the vehicle or container when
empty
Gross Weight – the weight of the vehicle or container and
the cargo
Net Weight = Gross Weight –Tare Weight
VEHICLE TYPESRIGID VS CURTAIN SIDED VS WINGBODY
Most commonly operate in AsiaIt is called wing body truck because it looks like a bird spreading the wings when the sides of the cargo bay are openedLoading and unloading are possible from both sides
Excellent access to all goodsLong and thin goods can also be put in and out easily.
WingsManual or hydraulicCanvas of rigid
VEHICLE TYPESWING BODY TRUCKS
Tank fitted to the chassisCargos carried
Liquids (petrol, water)Gases (oxygen)Powders (cement)Foodstuffs (milk, grain)
Cross contamination concernsIndustrialFoods stuffs
VEHICLE TYPESTANKERS
Rigid Tanker Tanker Trailers
Rigid or articulated formsOpen top body
Loaded by gravity (payloader / hopper / grab)Unloaded when body is tipped backwards (using a hydraulic arm) and tailgate released
Typical loads include aggregatesSoil, sand and stoneMajor contributor to road damage
Weighbridges used to check weight of vehicles
VEHICLE TYPESTIPPERS
Transport large (over sized) loadsUse of low loaders or other specialise equipment150T or more
Major impact on other road usersMay be restricted by route / time of dayMay require police / outriders / escort vehicle
Includes non road vehiclesMining trucks with payloads >300T
VEHICLE TYPESSPECIALIST
Tractor unit pulls two or more trailersTypical cargo / goods carried
FuelDry bulksGeneral freightLivestock
Australia - largest road trains in the world80 to 120 tonnesAlso found in Argentina, Mexico, USA and Canada
Used in remote areasLow populationLow road traffic volumes
Singificant impact on other road users
VEHICLE TYPESSPECIALIST - ROAD TRAINS
Section 1 Vehicle Types
Section 2 Technical Aspects
ROAD TRANSPORT ILECTURE STRUCTURE
TECHNICAL ASPECTSANATOMY OF A TRACTOR-TRAILER
Typical semi-trailer truck
1. Tractor unit (chassis) 2. Semi-trailer (detachable) 3. Engine 4. Drivers cab5. Sleeper (not present in all trucks) 6. Air dam – aero dynamics7. Fuel tanks 8. Fifth wheel coupling9. Cargo space 10. Legs11. Axles
11
Structural skeleton of the vehicleDetermines size and shape of the truck
Design is a major influence on fuel economyIncludes
CabAxlesEngineFuel tankBattery
TECHNICAL ASPECTSCHASSIS
Off-road vehicleLimited powerShunt (move) trailers in
Container terminalsRo-Ro terminalsManufacturing sitesDistribution centres
TECHNICAL ASPECTSTERMINAL SHUNTER UNITS
Key characteristicsEngine power (horsepower)
Maintain speed over long distanceSpeed of accelerationMore needed for long distance or high speed work
Pulling power (torque)Force to move vehicle from stationary startPower to pull up hill (gradient)More needed for heavier loads and greater gradient
Engine choice depends onJourney – long distance or local deliveryWeight of cargo (load)Road speeds
TECHNICAL ASPECTSENGINE
Number of fuels availableDiesel (most common)BiofuelsLPG / CNGElectricHybrid-electric
Major cost element30% operational costsRising fuel prices impact profits
Increasing focus on fuel efficiency viaDriving techniquesGood maintenance Tractor and trailer design (aero dynamics)Tyre & wheel designTare weight reduction
TECHNICAL ASPECTSFUEL
TECHNICAL ASPECTSFUEL
Derived: www.truckbuyersguide.gov.au
Fuel Details Advantages Disadvantages
Diesel • Standard • Widely available • Increasing cost• High emissions
Biofuels • Ethanol – from sugar cane or other plant materials
• Biodiesel –from vegetable oil or animal fat
• Lower emissions• Used by standard trucks
• Blended with other fuels• May void vehicle
warranties
LPG / CNG • Limited application for haulage – city (urban) deliveries
• Cheaper than diesel• Low pollution levels
• Typically retro-fitted• Cost of installation
Electric • Rechargeable battery• Limited haulage use
• Zero emissions • Expensive
Hybrid-electric • Conventional fuel with on-board rechargeable battery
• Best on local pick up and delivery
• Benefits from both technologies
• Better fuel economy (10-14%)
• Expensive• Negligible benefit for open
road driving
Combines conventional engine technology with electric propulsion system
Achieves better fuel economy and performancePort of Long Beach, USA
Testing hybrid tractor units to move containers Engine will not idle when not moving
Diesel units consume power when not movingTractors stand still 50 – 80% of time when in use
BenefitsMay be recharged from the electric gridEmissionsImproved energy efficiencySavings of 3,000 gallons / shunter / annum
TECHNICAL ASPECTSHYBRID VEHICLES
Distributes gross weight of the vehicle onto road surfaceProvides stability and motion of vehicle and even breakingNumerous axle / trailer combinations availableSubject to strict national regulations
TECHNICAL ASPECTSAXLES
Choice depends onTractor unit engineMileageCargo weightRoad conditions
ImpactsFuel efficiencyRoad noise
Maintenance importantUnder inflation
Fuel cost +6.25% if 10% under inflatedReduced tyre life by 10% to 40%
Blowouts (loss of control / serious accidents)
TECHNICAL ASPECTSTYRES
Towing mechanism between tractor unit and semi-trailerComprises
Horseshoe-shaped device (fifth wheel) on tractor unitCoupling pin (kingpin) on front of the semi-trailer
Once in position the semi-trailer landing gear is raisedAirlines and electrical leads link tractor to trailer
Provide power for lights / temperature controlBreaking capability
TECHNICAL ASPECTSFIFTH WHEEL (TRACTOR-TRAILER)
Fifth Wheel
Coupling Pin
Truck driving and operationPerformance monitoringTruck status / diagnostics
CommunicationsNavigation and routeingIT and office administrationVisibility of vehicle to office
Living accommodationSleeping quartersEntertainment systemsEating (microwaves…)
TECHNICAL ASPECTSDRIVERS CAB
TECHNICAL ASPECTSANATOMY OF A TRAILER
Depends on cargoShape WeightVolume
Access to cargo is important with respect toSecurityLoading / unloading at origin / destination
Facilities at origin / destination may impact body choice
TECHNICAL ASPECTSBODY
Number of design options availableTear drop trailers
Design reduces drag resistanceLafarge (UK)
Reduction in fuel costs by 10% Reduce carbon emissions by 120 tonnes per year Use of LNG will provide further cost / emission savings
TECHNICAL ASPECTSINCREASING EFFICIENCY BY DESIGN