Wednesday, July 8, 2009

The Bridges of Pakistan






Every year, the American Society of Civil Engineers (ASCE) puts out a very beautiful calendar on bridges all over the world. However there has never been any bridge from Pakistan on this calendar. There is not without reason. In the last six decades, Pakistan has not built a bridge of any aesthetic or architectural value.
Other than rail and road bridges, Pakistan also has numerous dams and barrages over major rivers. These are river blockage structures and gated spillways to control water flow and are often used for road traffic as well.



Rail traffic, however, requires heavier bridges than does the road traffic. Again unfortunately Pakistan Railway has hardly built any new rail lines since the British period. The railway system in Pakistan is almost one and half century old. The system is antiquated and so are the bridges. However at the time when some of these bridges were built, their design and construction like the Eiffel Tower in Paris was innovative enough that they were considered as engineering marvels of that time.

In the hilly areas of Kashmir, Frontier and Balochistan the bridges were and still are being built to cross valleys and the river gorges. These may be high bridges but their spans are generally short and foundations are placed either on dry land or in shallow waters of seasonal rivers and streams. Very often these are masonry arched structures with some use of steel beams and trusses, even though one occasionally comes across those single span rope bridges thrown over the river waters gushing through the narrow gorges. Pretty as they look, these rope bridges are not permanent structures and could be dangerous to vehicle crossing.


The biggest challenge in bridge building in Pakistan comes at the crossings of the five major rivers in Punjab and the Indus River in Sindh respectively. None of the governments of the past, imperial or otherwise, attempted to construct permanent bridges over these rivers as rivers were almost always used as another line of defense against invaders from the north and west. That is one reason one sees major old forts all along the south and east sides of the rivers and no permanent bridges. Invading armies waited till the end of the summer and crossed the rivers by using boat bridges constructed by tying boats side by side with ropes and then placing wooden planks to provide the smooth riding surface.

British on the other hand, after conquering the areas now constituting Pakistan in mid nineteen century moved the first line of defense all the way to the top of Hindu Kush Mountains. Thus freeing themselves to span the major rivers with permanent structures for both road and rail use. An era of large permanent bridge structures dawned in areas now constituting Pakistan.
Starting from north, the Attock Bridge on river Indus and the Jhelum Bridge over river Jhelum, both near the cities of the same names respectively, are noteworthy. Also are the rail bridges over river Chenab near Wazirabad and over river Ravi near the capital city of Lahore.

These are all truss structures made of smelted iron fabricated one unit at a time from structural steel. Although labor intensive these structures could be erected without the benefit of heavy industrial complexes or construction machinery. These are multi span bridges with masonry foundations constructed within the river beds. Even though the modern techniques of using coffer dams to construct large masonry footings in water were not available, the engineers were able to temporarily divert the rivers to the other side and thus construct the footings in dry grounds. Spanning of the five rivers allowed the colonial rulers to connect Punjab and beyond to their Imperial capital Delhi located in the Ganges valley in northern India.

The real engineering challenge for the bridge builders came with the need to link Punjab with Sindh by crossing river Sutlej and Sindh with Balochistan by crossing river Indus. Sites near the cities of Bahawalpur and Sukher were selected for the river crossings. These two bridges now in Pakistan are often referred in the history books.

William St. John Galwey, (1833-1891) an Irishman from Cork County was called upon to construct the Bridge over Sutlej. Earlier in his capacity as railway engineer he had successfully completed the construction of the Jhelum Bridge. The Sutlej Bridge also known as Adam Wahan Bridge is the only rail bridge over Sutlej River in Pakistan. Its opening ceremonies were scheduled to coincide with the coronation of Queen Victoria and hence in her honor was named The Empress Bridge.

Used Volvo Ec210b Lc Excavator Crawler For Sale

Used 2005 Heavy Volvo Ec210b Lc equipment for sale of Excavator Crawler type by Volvo Crawler dealer located at Boston Massachusetts, Browse the complete Volvo Crawler Excavator specification below with Volvo Excavator Crawler pictures and if you find the perfect equipment as per your requirment than you may contact this machinery seller.
Machine / Equipment Specifications :
Year : 2005
Category : Excavator
Subcategory : Crawler
Manufacturer : Volvo
Model : Ec210b Lc
Price : US $99,900
Location : Boston, Massachusetts
Condition : USED
Stock Number : 11171
Hours : 1,300

Used Caterpillar 816b Compaction Equipment Landfill For Sale

Used 1991 Heavy Caterpillar 816b equipment for sale of Compaction Equipment Landfill type by Caterpillar Landfill dealer located at Albuquerque New Mexico, Browse the complete Caterpillar Landfill Compaction Equipment specification below with Caterpillar Compaction Equipment Landfill pictures and if you find the perfect equipment as per your requirment than you may contact this machinery seller.
Machine / Equipment Specifications :
Year : 1991
Category : Compaction Equipment
Subcategory : Landfill
Manufacturer : Caterpillar
Model : 816b
Price : US $115,000
Location : Albuquerque, New Mexico
Serial Number : 15Z01187
Condition : USED
Stock Number : M409400
Machine / Equipment Specifications :
Year : 2006
Category : Lift
Subcategory : Boom
Manufacturer : Jlg
Model : 1350sjp
Price : US $174,000
Location : Cleveland, Ohio
Condition : USED
Drive : 4WD

Used Hamm Dv6.42 Compaction Equipment Smooth Drum For Sale

Machine / Equipment Specifications :
Year : 1995
Category : Compaction Equipment
Subcategory : Smooth Drum
Manufacturer : Hamm
Model : Dv6.42
Price : US $41,003 - (Price entered as 26,500 Euro)
Location : Veldhoven, The Netherlands
Serial Number : 37791
Condition : USED
Stock Number : BTR01686
Hours : 6,671

Used Deere 750c Lgp Ii Dozer Crawler

Year : 2004
Category : Dozer
Subcategory : Crawler
Manufacturer : Deere
Model : 750c Lgp Ii
Price : US $92,000
Location : Tampa (Lutz), Florida
Condition : USED
Stock Number : E031363
Hours : 6,650

Used Deere 750c Lgp Ii Dozer Crawler

Year : 2004
Category : Dozer
Subcategory : Crawler
Manufacturer : Deere
Model : 750c Lgp Ii
Price : US $92,000
Location : Tampa (Lutz), Florida
Condition : USED
Stock Number : E031363
Hours : 6,650

Wednesday, July 1, 2009

NASA Mars Lander Receives Award From Magazine

PASADENA, Calif. -- NASA's Phoenix Mars Lander has won recognition from Popular Science magazine as an innovation worthy of the publication's "Best of What's New" Grand Award in the aviation and space category.

The lander finished its work on Mars this month, and its team of scientists continues to analyze information that Phoenix sent home during more than five months of operating at a landing site in the Martian arctic. It landed on May 25, 2008.

The lander's robotic arm delivered soil samples to onboard laboratory instruments that analyzed the composition and examined particles microscopically.

"For 21 years, Popular Science's Best of What's New awards honor the innovations that make a positive impact on life today and change our views of the future," said Mark Jannot, editor-in-chief of the magazine.

More information on the award winners is online at http://www.popsci.com/bown/2008 .

The Phoenix mission is led by Peter Smith of the University of Arizona, Tucson, with project management at NASA's Jet Propulsion Laboratory, Pasadena, Calif., and development partnership at Lockheed Martin Space Systems, Denver. International contributions come from the Canadian Space Agency; the University of Neuchatel; the universities of Copenhagen and Aarhus, Denmark; Max Planck Institute, Germany; Imperial College, London; and the Finnish Meteorological Institute.

Working in Space in mars

Moon Rocket


I Reconized that the rocket machinaery is the Biggest machine Ever!

Jet engine

One of the most important developments in the long-term improvements in aviation safety was the jet engine. Between 1946 and 1958, the United States averaged three major plane accidents and 42 fatalities a year in accidents caused primarily by engine failures. Since the introduction of the passenger jet in the late 1950s, the number of crashes due to engine failure plummeted, as did the total number of plane accidents.
While traditional piston engines improved greatly through the 1930s and '40s, they did not offer satisfactory reliability. In fact, as power increased (an objective in developing military planes), reliable endurance tended to decrease. By the 1950s, the best piston engines available could only run 1,500 to 2,000 hours before they required overhauls.
All this changed with the jet engine. In 1958, National Airlines launched its jet service between New York and Miami. These early jet engines extended the "time between overhaul" (TBO) to 6,200 hours and then to 20,000 hours. Today, with proper maintenance, jet engines can perform up to 50,000 hours before a complete overhaul is needed.

The increased performance level of jet engines affects safety in a number of ways. Most obviously, the reliability of jet engines ensures that crashes due to engine failure are uncommon events. Jet engines also allow planes to fly longer and faster, enabling planes to travel to a different airport if their original destination proves unsafe for landing. Finally, powerful jet engines allow planes to fly above dangerous storms and turbulence.

Trimming Dozer

Bulldozer


Detailed Bulldozer Description

Specifications:
a) Power: 220HP
b) Weight: 25,700kg
c) Equals Komatsu D85P

Our Bulldozer comply with International Quality Standards and their quality and durability are fully guranteed.

Truck Crane Capacity 50 Ton (QY50K)


Product Description

We can supply truck crane series payload from 16 ton to 130 ton made in China.
QY16D truck crane payload 16 ton
QY20B truck crane payload 20 ton
QY25K truck crane payload 25 ton with four boom
QY25K5 truck crane payload 25 ton with five boom
QY30K5 truck crane payload 30 ton with five boom
QY35K truck crane payload 35 ton
QY40K truck crane payload 40 ton
QY50K truck crane payload 50 ton
QY60K truck crane payload 60 ton
QY70K truck crane payload 70 ton
QY80K truck crane payload 80 ton
QY100K truck crane payload 100 ton
QY130K truck crane payload 130 ton

All Terrain Cranes series made in China.
1. QAY25 All Terrain Crane Payload 25 ton
2. QAY130 All Terrain Crane Payload 130 Ton
3. QAY160 All Terrain Crane Payload 160 Ton
4. QAY200 All Terrain Crane Payload 200 Ton
5. QAY240 All Terrain Crane payload 240 TON

Option:
1. CE
2. Chinese EUROIII engine

STATEMENT:
YANCHENG FOREIGN TRADE CORP., LTD ONLY MR ZHANGJUN GOT XCMG FACTORY AUTHORIZATION CAN SELL XCMG PRODUCTS SUCH AS TRUCK CRANES, TRUCK MOUTED CRANES, ALL TERRAIN CRANES, CRAWLER CRANES, AND other PERSON IN YANCHENG FOREIGN TRADE CORP., LTD DO NOT HAVE RIGHTS TO SELL XCMG PRODUCTS FOR EXPORT.

Sand Making Machine


Detailed Sand Making Machine Description

Features:
a) Used in the third or fourth stage of crushing circuits
b) Feed rates: 40 - 360MT / h
c) Machine drive power: 60 - 400kW
d) Feed sizes: 35 - 60mm
e) Provides the greatest flexibility of application for crushing machines in
a wide variety of materials and circuits
f) Usually used to make man - made sand
g) Can crush rock into small pieces of just 0 - 15mm
h) Suitable for crushing hard rock into qualtiy sand
i) High quality, low cost and easy to operation
j) Better than other crusher in versatility, easy
installation, capacity of production, smoothness of operation, reliability and hassle - free
performance

Models available:
a) PCL - 600
1) Max. feed size: 35mm
2) Capacity: 6 – 15MT / h
3) Weight: 5.6MT
4) Power consumption: 22 - 55kW
5) Rotation of impeller: 2000 - 3000r / min
6) Dimensions (L x W x ): 2500 x 1600 x 2260mm
b) b) PCL - 750
1) Max. feed size: 45mm
2) Capacity: 10 – 30MT / h
3) Weight: 7.3MT
4) Power consumption: 45 - 90kW
5) Rotation of impeller: 1500 x 2500r / min
6) Dimensions (L x W x ): 2780 x 1800 x 2700mm
c) PCL - 900
1) Max. feed size: 50mm
2) Capacity: 15 - 35MT / h
3) Weight: 12.1MT
4) Power consumption: 90 - 180kW
5) Rotation of impeller: 1200 - 2000r / min
6) Dimensions (L x W x ): 3900 x 2160 x 2770mm
d) PCL - 1050
1) Max. feed size: 60mm
2) Capacity: 25 - 75MT / h
3) Weight: 16.9MT
4) Power consumption: 150 - 264kW
5) Rotation of impeller: 1000 - 1700r / min
6) Dimensions (L x W x ): 4660 x 2450 x 3660mm
e) PCL - 1250
1) Max. feed size: 60mm
2) Capacity: 30 - 80MT / h
3) Weight: 22MT
4) Power consumption: 264 - 440kW
5) Rotation of impeller: 850 - 1450r / min
6) Dimensions (L x W x ): 5600 x 2950 x 4000mm
f) PCL - 1350
1) Max. feed size: 60mm
2) Capacity: 50 - 140MT / h
3) Weight: 26MT
4) Power consumption: 320 - 440kW
5) Rotation of impeller: 800 - 1193r / min

Road Roller


Detailed Road Roller Description

Specifications:
a) Power: 80kW
b) Operating weight: 12,000
c) Hydraulic double drive

We are committed to doing our best for you, and welcome inquiries for Road Roller.

Truck Crane Payload 16 Ton (QY16D)


Product Description

We can supply truck crane series payload from 8 ton to 130 ton made in China.
QY8D truck crane payload 8 ton
QY12 truck crane payload 12 ton
QY16D truck crane payload 16 ton
QY20B truck crane payload 20 ton
QY25K truck crane payload 25 ton with four boom
QY25K5 truck crane payload 25 ton with five boom
QY30K5 truck crane payload 30 ton with five boom
QY35K truck crane payload 35 ton
QY40K truck crane payload 40 ton
QY50K truck crane payload 50 ton
QY60K truck crane payload 60 ton
QY70K truck crane payload 70 ton
QY80K truck crane payload 80 ton
QY100K truck crane payload 100 ton
QY130K truck crane payload 130 ton

All Terrain Cranes series made in China.
1. QAY25 All Terrain Crane Payload 25 ton
2. QAY130 All Terrain Crane Payload 130 Ton
3. QAY160 All Terrain Crane Payload 160 Ton
4. QAY200 All Terrain Crane Payload 200 Ton
5. QAY240 All Terrain Crane Payload 240 Ton

Option:
1. CE, EPA approved
2. Chinese engine EURO III

'Dual-Power' Hydraulic Wheeled Knuckle-Boom Grabbing Crane (QLYS20DZ)

Product Description

We can supply "Dual-power" Hydraulic Wheeled Knuckle-Boom Grabbing Crane with different attachment made in China.

1. QLYS6DZ payload 6 ton
2. QLYS10DZ payload 10 ton
3. QLYS15DZ payload 15 ton
4. QLYS20DZ payload 20 ton

Option attachments:
Hydraulic Log Grabber
Hydraulic Mussel Grabber
Hydraulic Closure Grabber
Loosing material grabber
Holding pliers grabber
Rubbish Copper Grabber
Hydraulic power station

Truck Crane Payload 40 Ton (QY40K)


Product Description

We can supply truck crane series payload from 16 ton to 130 ton made in China.
QY16D truck crane payload 16 ton
QY20B truck crane payload 20 ton
QY25K truck crane payload 25 ton with four boom
QY25K5 truck crane payload 25 ton with five boom
QY30K5 truck crane payload 30 ton with five boom
QY35K truck crane payload 35 ton
QY40K truck crane payload 40 ton
QY50K truck crane payload 50 ton
QY60K truck crane payload 60 ton
QY70K truck crane payload 70 ton
QY80K truck crane payload 80 ton
QY100K truck crane payload 100 ton
QY130K truck crane payload 130 ton

All Terrain Cranes series made in China.
1. QAY25 All Terrain Crane payload 25 ton
2. QAY130 All Terrain Crane Payload 130 Ton
3. QAY160 All Terrain Crane Payload 160 Ton
4. QAY200 All Terrain Crane Payload 200 Ton
5. QAY240 All Terrain Crane Payload 240 Ton

Option:
1. CE, EPA approved.
2. Chinese EURO III engine.

Wheel loader 244j

ENGINE
Manufacturer/Model John Deere / 4024T
Net Rated Power hp (kW)@Rated rpm 59 (44) @ 2800
Net Peak Power hp (kW)@ rpm 64 (48) @ 2600
# Cylinders and Displacement cu in. (L) 4 - 149 (2.4)
Gross Peak Torque lb-ft (N-m)@ rpm Not published
Net Peak Torque lb-ft (N-m)@rpm 163 (221) @ 1600
Calculated % Torque Rise 47.3%
ELECTRICAL Volts/Alternator amps 12 / 65
TRANSMISSION
Type Hydrostatic
Speed Ranges F X R Infinite
Forward 18.6 (29.9)
Reverse 18.6 (29.9)
DIFFERENTIAL
Front Traction Device Locking std
Rear Traction Device Conventional only
Front Axle Disconnect Not applicable
FINAL DRIVE LOCATION & TYPE Outboard planetary
SERVICE BRAKES
Type Oil (wet) disc
Location Driveline
Actuation Hydraulic/footpedal
HYDRAULIC SYSTEM
Pump Type Gear
Pump Flow gpm (L/min.) 17 (64)
System Pressure psi (kPa) 3190 (21980)
LOADER AND BUCKET
Bucket range, Min.-Max. cu yd (cu m) 1.0 - 1.4 (0.8 - 1.1)
Breakout force, Std Bucket lb (kN) 10,792 (48.0)
Ride Control Opt
Full Height lb (kg) 6,407 (2906)
Ground Level lb (kg) 9,892 (4487)
SPECIFICATIONS BASED ON
Std. Bucket Size cu yd (cu m) 1.0 (0.77)
Teeth or bolt-on edge on Std Bucket Bolt-on
Tire Size 365/70R18
Counterweight lb 0
TIPPING LOAD
Straight lb (kg) 8,457 (3836)
Full Turn lb (kg) 7,718 (3501)
DIMENSIONS
Height of Hinge Pin ft in. (mm) 10' 6.4" (3210)
Dump Clear @ 45 deg ft in.(mm) 8' 4.4" (2550)
Reach @ 7 ft in. (mm) Not published
Reach @ Full Height ft in. (mm) 2' 8.2" (820)
Wheelbase ft in. (mm) 7' 0.6" (2150)
Clearance Circle ft in. (mm) 24' 2.6" (3690)
Overall Length ft in. (mm) 17' 4" (5280)
Height Top of Cab ft in.(mm) 8' 11" (2720)
Ground Clearance in. (mm) 11.6" (2149)
CAPACITIES
Fuel Tank gal (L) 22 (81)
Hydraulic Reservoir gal (L) Not Published
SAE OPERATING WEIGHT LB (kg) 11,552 (5240)