light-weight emergency tent (lwet) - · pdf filespecifications of light-weight emergency tent...

Version 4.0 June 2006

SPECIFICATIONS

Light-Weight Emergency Tent (LWET)

Specifications of Light-weight Emergency Tent

Version 4.0: June 2006

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1. Background 1a. Two main items used by UNHCR to provide shelter in an emergency situations have been plastic sheeting

and canvas tents. They both have their advantages and disadvantages. 1b. Plastic sheeting though light in weight, hardly provides a solution to shelter and canvas tents though with a

lower cost, they are very heavy, have limited shelf life and costly to transport. 1c. In continuation of UNHCR’s on-going efforts to improve preparedness for emergencies, the relevant sections in

UNHCR began the process of developing a Light-weight Emergency Tent (LWET). 1d. With the set criteria such as lightweight, longer shelf life and durability, UNHCR embarked on

development of such a tent using different type material, different type of poles and a different shape. 1e. The work was carried out by benefiting from both Geneva and field based review. 1f. The following pages are result of a joint efforts within UNHCR, which is presented in text specifications of

the developed tent along with the related pictures. It is important to mention the following two points:

Weight of this tent is 41.5 Kg (including steel pegs, a hammer and packaging) and packed in a hand bag for the ease of handling, it maybe noted that UNHCR traditional canvas tents of 4.00m x 4.00m, the ridge type is 80.0 kg and centre pole tent is 110.0 kg with the same floor area but more living space.

In addition to the its lightweight and long shelf life, this tent has two separate doors at each end, is fully mosquito proof and is easy to pitch. The tent has a partition dividing it into two separate space to ensure privacy and dignity. This is maybe the first time that a family tent has partitioning.

1g. Great attention has been given to the details for providing a suitable solution hence production of tent

requires best possible craftsmanship in line with craftsmanship of leisure tents.



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2. Shape, Size and Construction 2a. The tent is semi-circular or tunnel shaped with centre height of 210 cm, width of 300 cm and length of

550 cm. 2b. It consists of two full layers or double fly i.e. a water proof outer shell and an inner tent with 12 cm

continuous distance between them. 2c. The size/total useable floor area of the outer shell is (3.00 m x 5.50 m) 16.50 m2 sufficient for a family

of 4-5 persons at the rate of 3.5 m2 sleeping area per person.



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2d. The inner tent, which is with integrated flooring (“bathtub” ground sheeting), is supported by or hung from the outer shell. However when occupied, the inner tent acts as stabilizer of the outer shell and hence provides greater stability to the tent itself.

2e. The outer shell acts as a pure “shell” and not a “tent” and hence with no mud flap which in turn reduces

the cost, weight and increases the durability of tent.



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3. The outer shell (Specifications) 3a. Woven polyester of Ripstop weave with number count of wrap 64 and weft 42 threads per inch. 3b. Basic weight 150 -170 grams / m2. 3c. The outer shell is of white colour from both sides. 3d. Free of weaving defects that would have a negative affect on strength, water profess and durability. 3e. Water proof to withstand a minimum of 3000 mm of static water column, subject to testing. 3f. Fabric should be stabilised against decomposition (termite,

mold, mildew and rot). 3g. Stabilised against UV degradation for 2,000 hours, subject to

testing. 3h. Fire retardant coating to reduce flammability by either

polyurethane or aluminium coating or others in accordance with CPAI-84 1955 standards.

3i. Integrated and continuous Sleeves (5 sleeves or loops) with no

breaks (for the ease of rod insertion) to house the tension rods for holding the outer shell from which the inner tent would be suspended. The width of sleeve should be large enough for inserting the rods easily but not too large to allow unnecessary movement of rod within the sleeve.



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3j. All seams to be double locked stitched, and supported with anti-leak/anti-seepage water taping.

The supplier will insure that the stitch count and thread used for all parts of the tent are appropriate for the material and will produce strong, long lasting (both on the shelf and in use) and are of highest degree of craftsmanship. Low quality workmanship at any point is categorically unacceptable.

3k. Strong and rot proof ground fixation at 10 specified

locations at the ends of sleeves around the perimeter of the tent (5 on each side). The fixation ends with a metallic triangle as shown in the picture. End of rods will be inserted in the hole and fixed to the ground.

3l. The outer shell should have 10 triangular reinforcement as shown in the picture at each fixation point to

prevent tearing of the material. The reinforcement triangle is about 15 cm on the sides and 25 cm on the bottom with the same material of outer shell.



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3m. A strap with width of 38 mm and strength to carrying 100

Kg of load, rot proof equipped with a metallic triangle as shown in the picture and a metallic buckle near one side of the tension rod to hold the both ends of tension rod at a distance of 3.00 meters from one another. We have provided two pictures on the way this should be done.

3n. The outer shell at each end of the tension rods should be fixed

to the strap in order to avoid roll-up of outer shell along the tension rod.



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3o. Four integrated windows size 40cm x 30 cm (two on each long sides) with mosquito nets of minimum aperture, (for outer shell, B18 which is used for its strength and ventilation and for inner tent, B4 for preventing mosquitoes to pass through) and fully covered flap equipped with Velcro all around the perimeter. The windows should be able to be rolled up and fixed up with buttons. The mosquito net for the inner tent (doors, windows and ventilations openings) and outer shell should be long lasting insecticide treated in accordance with WHO standards.

WHO recommended insecticides for treatment of mosquito nets for malaria vector control.

INSECTICIDE FORMULATION1 DOSAGE2

Alpha-cypermethrin Cyfluthrin Deltamethrin Etofenprox Permethrin

SC 10% EW 5% SC 1% and WT 25%3

EW 10%3 EC 10%

20-40 50 15-25 200 200-500

1. SC= suspension concentrate; EW=emulsion, oil in water; WT=water dispersible tablet; EC: emulsifiable concentrate.

2. Milligrams of active ingredient per square meter of netting 3. WHO specifications under development



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3p. Four integrated ventilation flap openings with mosquito net of minimum aperture covered with D shaped ring hood. The size of each ventilation opening shall be 20 cm x 15 cm,



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3q. There are six side ropes (three

on each side of the tent). The connecting mechanism of the side ropes to the outer shell should be double fold in triangular shape with the same material as outer shell, with a base of about 22 cm and sides of about 21 and 11 cm connected to both sides of the sleeve holding the tension rods reinforced in the end of about 4 cm wide and equipped with webbing to knot the side rope. The location of this triangle is approximately 125 cm from the ground level to the centre of the triangle. It is important the connection envelopes the tension rod so as he distribution the tension force of the rope transmitted to the to the pole and not the fabric.



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3r. There are eight connections for

the guy ropes (four at either end of the tent). These connections should be stronger than the side ones as they take more pressure and are important to keep the tent straight. We have therefore provided a different mechanism than the side connections.

They are made of double webbing stitched to the either side of the sleeve. The outer shell at the place of stitch is reinforced by a triangle of 16cm x16cm x 16cm. The connecting mechanism of the guy ropes (ropes on either end of tent) is a handle system in which two pieces of strong webbing of 4 cm wide in white colour as per details of the drawing are used. The connection mechanism for the lower guy rope is about 115 cm in line with the connection of side ropes and the upper one about 180 cm from the ground along the sleeve. Please see the next page for the pictures of this system.



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Double white coloured webbing with reinforcement as described in the above paragraph under (3r).



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3s. The outer shell should have a connecting mechanism under each tension rod 25 cm apart from each other so that the inner shell can be hanged from it. Both the outer shell and the inner tent should be with be equipped with this connecting mechanism (webbing and rust proof metallic ring from the outer shell and strap from the outer tent material and toggle from the inner tent) at every 25 cm to be hung from the outer shell from all 5 tension rods. One single mechanism should be strong enough to carry or withstand a weight of about 10kg. Webbing and tent material as shown in the picture should be the only connector fabrics used. Care should be exercised that the stitches are strong enough to withstand the load.



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3t. One chimney outlet of 12 cm in diameter made of a special fire resistant fabric (apron) to with stand heat up to 500 degree centigrade.

3u. The hole should be able to be closed tightly to avoid rain and

moisture infiltration when heating of the tent is not required. 3v. The outlet should be wider towards the bottom to reach a

diameter of 30 cm where it will be stitched to the tent. It would be located in the fourth section (fourth out of four sections) ¾ from the end of tent and located on the side of the tent. The centre of the hole would be about 155 cm from the ground covered with the same material of outer shell covered 60cm X 60cm equipped with Velcro similar to the way windows are covered. This is to prevent any water infiltration when stove is not used. The seam on the upper part should be treated with water sealant as other seams. The outlet will also have removable cover from the inner tent.



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4.The Inner Tent (Specifications) 4a. The inner tent is the same shape as the outer shell but 24 cm

narrower leaving minimum of 12 cm gap on each side (and all around) between the outer shell and inner tent with useable floor area of maximum 15.18 m2 [5.50m x (3.00-(0.12 + 0.12))m]. The height would be maximum of 1.98m (2.10m-0.12m).

4b. Made of breathable material from a blend of polyester and

cotton 55/45; yarn count 25s x 25s where as 65/35; yarn count 24s x 24s would also be acceptable.

4c. Basic weight of 120-130 gram/m2, Ripstop weave and fire

retardant. 4d. The inner tent shall be blue in colour. 4e. All seams should be double stitched.



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4f. One integrated door on either

end of the inner tent (total two doors) with mosquito net and zipper of No. 10 (9mm) moulded plastic with double pull slider opening upwards. The doors shall have height of 160 cm and a width of 100 cm having a 25 cm threshold of same material as the ground sheet.

4g. The mosquito net should be of

with fine mesh (mesh B4) and equipped zippers No. 8 or 10 moulded plastic with double pull slider on both sides and Velcro on the bottom to prevent mosquitoes to enter the tent. A dart or fold (i.e. a piece of excess material) if needed should be included in both door and mosquito net to reduce stress on the zippers.



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4h. The front and back of the inner tent including the doors

should be double fold; outer fold same material of outer shell and inner fold same material of inner tent.



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4i. This double effect will continue to cover the both ends of inner tent towards the middle for about 30 cm deep as well.

4j. These provisions increase the durability of the tent, provides

cooler temperature and resistance to rain accepting the slight increase in the weight.

4k. Zipper No. 10 (9mm) moulded plastic with double pull slider

the door of inner tent with a back up of button.



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4l. Integrated strong ground sheeting made of polyethylene,

weight: 200 gram/ m2, water proof to withstand 2000 mm of water column and double stitched to inner tent. The stitching of the ground sheet to the inner tent should be about 20cm above the ground to ensure better resistance to possible water infiltration. All seams should be treated with anti-leak/anti-seepage water sealant/tape.

4m. The ground sheeting shall be of dark blue in colour so as

not to stain easily after some usage and same as UNHCR specified plastic tarpaulin that has proven best for such usage. It is made of woven high density polyethylene fibbers; warp x weft: 12/14 x 12/14 per square inch, laminated on both sides with low density polyethylene; Material weight: minimum 200 gr/m2 +/- 5%; Tensile strength: minimum 600 n both directions of warp and weft (bs 2576, 50 mm grab test, or equivalent); Tear resistance: minimum 100 n both directions (bs 4303 wing tear or equivalent); Flammability (CPAI-84).



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4n. Inner tent shall be supported by the outer shell (hung from the outer shell). All rings shall be of rust

resistance material. 4o. The inner shell should have a

connecting mechanism under each tension rod 25 cm apart from each other so that the inner shell can be hanged from the outer shell. Both the outer shell and the inner tent should be equipped with this connecting mechanism ( webbing and rust proof metallic ring from the outer shell and strap from outer tent material and toggle from the inner tent) at every 25 cm to be hung from the outer shell from all 5 tension rods. One single mechanism should be strong enough to carry or withstand a weight of about 10kg. Webbing and tent material as shown in the picture should be the only connector fabrics used. Care should be exercised that the stitches are strong enough to withstand the load.



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4p. Distance between the outer shell and the inner tent shall be

12 cm minimum. This is important as it has direct effect on the heat transfer, hence the distance should not be less than 12 cm that has been prescribed,

The connection of the four corners close to the ground will have the adjustable buckle as shown in the picture



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4q. Four integrated windows for ventilation in line with the

outer shell window with mosquito net and fully covered with the same material equipped with either Velcro or buttons, to be rolled up (hold-up with either Velcro or buttons). The windows shall have a height of 30 cm and a width of 40 cm,

4r. Four integrated ventilation openings at the top (two on

each side) to be aligned to the ventilation opening hood of the outer shell (with no cover) ,



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4s. The inner tent should be partitioned in the middle dividing

the tent into two sections of 2.75m X 2.76m = 7.59 m2, 4t. The partitioning consists of two sections, which will be

stitched to the inner tent with about 40 cm overlapping in the middle equipped with buttons. The partition can be rolled back to the sides with tie strap to hold it on both sides of the tent. The material would be the same as inner tent, and must not be of transparent material.



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4u. The inner tent will have a canopy of about 150 cm stitched across the top and coming out from the tent a distance of 100 cm on the both ends of the inner tent. The canopy which is of the same material as the outer tent, is stitched to the upper ends of the inner tent equipped with two guy ropes that connect its two outer corners to the existing pegs,

4v. A pocket of clear plastic for inserting an A4 paper in the

landscape way to be fixed to both ends of the inner tent on the left side of the door. This should be close to the edge of the tent and 1.00 m from the ground taped with water sealing tape.



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5. Support System / Tension Rods (Specifications) 5a. Tension rods should be of solid fibre glass reinforced

with black polyethylene wrapper, with in odd number of tubular sleeves or internal rod connector pins to provide with the desired length, shape and a standing free height of 210 cm at the centre of the tent. The rod diameter to be of 15 mm (12.4 mm fibreglass and with wrapper 15.36 mm in diameter).

5b. There will be five tension rods of 5a above dividing the

tent into four equal segments. The tension rods should be divided into odd number.

5c. The rods should be “shock-corded” (having a cord inside the rod). The joints shall be easy to assemble and

should be sufficiently reinforced to avoid any possible breakage as these are the weak points in the tension rods.



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5d. The ends of the tension rods are anchored to the ground with an aluminium or bras eyelet in the strap connecting the both sides of tension rod in place,

5e. The metallic ends of the

tension rods should be at least 5.0 cm long at each end to ensure better fixation of the frame to the strap and to the ground,

5f. One extra rod should be

included in every tent. This is to offset any undetected weakness or defect that the rods may have.



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6. Side and Guy Ropes (Specifications) 6a. Guy ropes should be made of polypropylene fibres in three

strands, having a diameter of 06 mm and length of 3.00 meters for the side ropes and four guy ropes and 3.5 meters for the other four guy ropes that are attached to the upper part of either end of the tent,

6b. The strength of the guy ropes should not be less than 50 Kg, 6c. Guy ropes should be UV resistance, 6d. Four guy ropes on each end and three on each long side

of the outer shell hence gives total of 14 guy and side ropes. All ropes are equipped with a simple and light tightening mechanism. This should be either of a light metallic or a varnished wooden nature. It should be noted that there is provision of one peg for two guy ropes and one for each side ropes hence total 10 pegs.

6e. Guy and side ropes should be pre-knotted to the outer tent.

This will facilitate installation of the tent in the field and prevents removal of the ropes during the installation of tent.



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7. Pegs (Specifications) 7a. Pegs for the outer shell shall be of corrugated (deformed)

steel having a length 30 cm ,including the bend and, diameter 12 mm, with provision of a smooth “U” shaped bend to hook and tie up the guy ropes and tapered in the other end. Our experience has shown that the aluminium pegs in real refugee situation do not perform as desired hence we need to compromise weight for practical performance i.e. to use iron pegs,

7b. Total of 10 corrugated pegs for outer shell are required. The

corrugation will increase the shear force resistance. The pegs are tapered at one end to ensure easy anchoring into the ground,

7c. It may be noted that in this design we have eliminated pegs

for inner tent. 7d. A hammer strong enough for hammering the pegs



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8. General Conditions 8a. The procedure of erection of tent

should be clearly and thoroughly written in a step by step manner and shown using drawings or pictures to be packed individually in each tent,

8b. Markings to be printed in blue indelible

ink on both sides of the tent and on the top of the tent (to be positioned horizontally) for maximum visibility. The width of marking would be 120cm and the height proportionate to the width without any distortion of the logo and letterings (approximately 35cm).

8c. Both the outer shell and inner tents shall be treated with a fire retardant chemicals. 8d. Inspection will take place in accordance to Para 18 of “Doing business with UNHCR dated November 2002”, 8e. The outer shell, the inner tent and all the accessories shall be packed in one single bag made out of the

outer shell material with a carrying handle (Pic 1 and 2). The bag will be in a strong transparent polyethylene (Pic 3) and covered with Polyethylene bag Pic 4 . It will have two plastic straps (Pic 4) to hold it together. Please see the related pictures.

120 cm

8g. The craftsmanship on this product needs to be of highest quality and tolerances carefully taken into consideration for maximum performance.

These specifications will be in effect for at least two years and any changes by any entitity, even for their own use, requires prior consultation and approval of UNHCR in order to uphold the integrity of the original concept and design of this well received product



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Working Instructions for Inspection of LWET

(Construction inspection and laboratory tests) Reference LWET Specification Revision 4.0

Description of Items Ref. spec. Suggested standard for testing Specifications/Results 1. Background 2. General 1-2 All

Size 2.a 550cm x 300cm x 210cm Weight (around 41.5) 1.f This is the maximum, less will be a welcomed

3. Outer Shell 3 All

Material 3 a-h ISO 1833-1977/A-1980 (E) ISO 811-1981 ISO 7211/2-1984 ISO 7211/5-1984 ISO 3801-1977 CPAI 84-1955, Section 6

To be tested / verified by the inspection company (laboratory)

Fabric defects 3.f To be checked Color 3.c Refer to the approved sample if available No cut pieces 3.j (Panels should be in one piece to reduce chance of leakage) Stitches 3.j Double locked stitched Seam taping 3.j To be tested / verified by the inspection company (laboratory) Straps (Bottom) 3.k Withstand 100 Kg Buckles 3.m Withstand 100 Kg Triangle 3.l Refer to the sample Fixture/Buckles 3.m, n Refer to the approved sample if available Windows (size, function) 3.o 40cm x 30cm Treatment of the nets 3.o WHO Standards WHO standards Ventilation 3.p 20cm x 15cm



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Mesh 3.o Refer to the approved sample if available Connection of ropes (ends) 3.r Refer to the approved sample if available Connection of ropes (sides) 3.q Refer to the approved sample if available Connection of inner tent 3.s Refer to the approved sample if available Chimney material 3.t To be tested / verified by the inspection company (laboratory) Chimney location 3.u-v Refer to the approved sample if available

4. Inner Tent 4 All

Material 4.a-c ISO 1833-1977/A-1980 (E) ISO 7211/5-1984 ISO 3801-1977 BS 7209-1990

To be tested / verified by the inspection company (laboratory)

Color 4.d Refer to the signed sample Stitches 4.e Double locked stitched Door 4.f -g 100cm (width) x 160 cm (height) Double fold 4.h Refer to the approved sample if available Mesh 4.g WHO standards Refer to the approved sample if available Rain flap (30 cm) 4.i Refer to the approved sample if available Zipper 4.k Refer to the approved sample if available Ground sheet 4.l-m BS 4407-1988 (2002)

BS 4303-1995, wing Rip test BS 2576-1986 (1955) ISO 3801-1977 CPAI 84-1955, Section 6

To be tested verified by the inspection company (laboratory)

The Distance (gap) 4.o-p 12 cm, Refer to the approved sample if available Windows (size and

function) 4.q WHO standards 40cm x 30cm, Refer to the signed sample

Ventilation 4.r Refer to the approved sample if available Partition 4. s, t Refer to the approved sample if available



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Canopy 4.u Refer to the approved sample if available Pocket 4.v Refer to the approved sample if available

5. Tension Rods All 5 Rod Quality 5.a To be tested / verified by the inspection company (laboratory) Odd no. of rods 5.b 9, 7 or 5 sections Length of Ends 5.e 5.0cm the point as in the specifications Spare 5.f One piece

6. Ropes All 6 Quality of ropes 6.a,b,c To be tested / verified by the inspection company (laboratory) Number of ropes 6.d 14 pieces Pre-knotted 6.e 14 locations for guy and side ropes and 2 for canopy Tightners 6.d 14 pieces

7. Pegs All 7 Number, Dimension 7.a, b 10 pieces and 12 diameter, corrugated Shape, form 7.a “U” shaped bend Length 7.a 30 cm Hammer 7.d Strong enough for hammering the pegs

8. Conditions All 8 Pitching Instruction 8.a One booklet, instruction UNHCR Marking 8.b Three markings, Refer to the approved sample if available All fire retardant 8.c CPAI 84 - 1955 To be tested / verified by the inspection company (laboratory) Inspection 8.d All related laboratory and construction inspection. Packaging 8.e Refer to the approved sample if available Craftsmanship 8.g Refer to the approved sample if available

Comments Any other issue / special attention by the inspection company



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Inspection standard adopted: ANSI/ASQC Z1.4 - 1993 Additional suggested specifications / standards:

UV 2000 hrs bench mark as per specifications. Chimney fabric 500 oc degrees bench mark as per specifications. WHO recommended insecticides for treatment of mosquito nets for malaria vector control.

Inspection level II AQL Critical defective: Not Allowed, Major defective: 2.5, Minor defective: 4.0

1. Sample size: 80sets (Shipment quantity: 501-1200 sets) need 2 man-days (2 inspectors working one day).

2. Sample size: 125sets (Shipment quantity: 1201-3200 sets) need 2 man-days (2 inspectors working one day).

3. Sample size: 200sets (Shipment quantity: 3200-10000sets) need 3 man-days (2 inspectors working one day).

4. Sample size: below 80sets (Shipment quantity: below 501 sets) need 1 man-days (1 inspector working one day). Note : Sample size for on-site inspection is taken from the AQL table. Ghassem Fardanesh Snr. Physical Planner Technical Support Section/DOS 30 June 2006



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Notes: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

light-weight emergency tent (lwet) - · pdf filespecifications of light-weight emergency tent...

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