One Way Webbing Sling

A ka tsela e 'ngoe ho betsa letjeketjane is a rated polyester sling bought for one journey: it is fitted to the load, travels with it and is written off against that job instead of being returned to a sling store. This page covers the closed loop e sa feleng form — the shape specified for pipe, tube and bundling work, because a loop wraps a cylinder instead of hooking it. Mefuta e tloaelehileng: 1 t ho 12 t, bophara ba sehlopha 25 mm ho 300 mm, ntlha ya polokeho 5:1, 6:1 kapa 7:1, bolelele ba loop 0.5 m ho 100 m, marked to BS EN 1492-1.

What “one way” decides, and what it does not

The phrase describes the commercial life of the article, not its quality. A one way sling is manufactured, bopaki bo kentsoeng, colour coded and labelled to the same standard as a sling that will be inspected for years; the difference is that it leaves the store once and does not come back.

Three practical consequences follow. Ho joalo issued with the load, so it becomes a line on the packing list rather than an item in a sling register. Ho joalo inspected once, mothating wa taba, while a fault can still be replaced from the same consignment. And its print is its whole record: moeli oa mojaro o sebetsang, bolelele, factor and batch are the only traceability the band will ever carry, so the marking has to survive a lorry, a container and a loading bay — not just the production line.

What it does not change is the engineering. A narrow band or a lower factor chosen because “it is only going one way” is not a saving; ke moeli o sa lekanngoang o nkiloeng holim'a phahamiso. The figure that applies is the figure printed on the band, for the arrangement actually used. Buyers who need the returnable version of the same loop should read the letsoai le le leng le sa feleng le bataletseng page instead.

Why a closed loop is the right form for pipe, tube and bundles

An endless webbing sling is a band joined to itself. There is no eye to line up against a machined pipe end, no stitching stack at the bearing point and no shackle, hook or thimble anywhere on the article. On round loads that single property does most of the work.

• It cannot mark a coating. Galvanising, fusion bonded epoxy, three layer PE and paint are all damaged by the same things: a steel edge, a sliding hook and point pressure. A woven polyester face addresses all three. Nothing metallic contacts the pipe, and the load never slides against a fitting.
• The choke holds itself. Passed round the pipe and back through the loop, the band tightens as the load rises. On a cylinder the contact line is a full wrap rather than two point contacts, which is why a loop resists slipping along the axis and does not walk towards the pipe end during a pick.
• The load stays centred. Because the band wraps symmetrically, the pick point sits over the centre of gravity of a joint or bundle rather than off one side — the usual cause of a tilted, eccentric lift and of one sling taking more than its share.
• Pressure is spread by width. Thin wall PVC, PE and stainless tube dent under a narrow band. A 100–200 mm face turns a point load into a low pressure band, which is the single most effective protection on a soft or thin walled pipe.
• Nothing to lose and nothing to thread. A band with end fittings can arrive with the fittings gone. A loop is one piece of webbing: it is either there or it is not, and the person re-slinging at the far end needs no rigging plan to use it.

Where a one way webbing sling is used

The loop is chosen where the load is wrapped rather than hooked, and where the surface matters as much as the tonnage. On a joint lifted on its own, one loop goes round the pipe near each end and the two legs meet at the hook; on a bundle, one loop per pick position is choked round the pack. The applications below are the ones this range is most often bought for, and each one puts a different line on the enquiry.

Specifications of the one way webbing sling

The figures below describe the standard build. Width is not a free choice: it follows from the working load limit and from the safety factor, so the same tonnage appears at three widths. Loop length, ply, colour and print are made to the order.

Choosing the size: the figure from the pick, the width from the surface

Two decisions are made separately and in this order. The moeli oa mojaro o sebetsang comes from what one pick has to carry, divided by the mode factor of the hitch — not from the mass of the load as weighed. The bophara then comes from the surface being wrapped: a coated pipe and a painted machine at the same tonnage do not want the same band.

Bolelele: the two conventions, and why the mistake is expensive here

Loop ha e na lipheletso tsa ho lekanya lipakeng, so the trade quotes the same article two ways. The two figures differ by about a factor of two, and on a one trip band the error surfaces at the far end — in front of a customer, ha ho na sehlopha sa bobeli seo u ka fapanyetsanang ka sona.

What the same loop carries in each hitch

The figure on the label describes the vertical arrangement only. All three hitches are rigged without any change to the article, which is why the arrangement has to be stated before the width is fixed.

The choke is the arrangement a loop is bought for, and it is also the one that costs 20 % of the printed figure. A 4.5 t pipe bundle choked on a 5 t loop is an overload, not a margin — the answer is the next width up, not a longer band.

Coating and surface compatibility

Ho tshwaya, label and what it has to survive

On a single trip article the print is the record, so the marking is a specification line rather than a detail. Four things belong on the label: moeli oa mosebetsi, the loop length with its convention, ntlha ya polokeho, and the reference the despatch actually uses — a batch, nomoro ea pakete, nomoro ea odara kapa nomoro ea hau ea karolo. That reference is what ties the band on a quay to the line on a packing list in an office.

• E balehang ka mora leeto, eseng kamora tlhahiso. Small, low contrast print on a face that enters the choke will not be read at the far end.
• Kenya mebala joalo ka mocha oa bobeli. Mmala o le mong ka mofuta oa pakete, per customer or per tonnage lets a container of identical bands be sorted at a glance.
• Printed to your string. The label can carry your reference in the exact case and format you send, 'me lihlopha li ka kenngoa ka har'a krete, e tlamelletsoeng ka sekoting kapa e tlanngoeng ka bongata, e ngotsoeng ka pakete.

The single inspection, and what it looks at

A one trip band is checked once, ka taba, while a fault can still be replaced from the same consignment. Look at four things, ka tatellano ena: se lohang moo se kopanang le moroalo (maqeba, ho khopa, sefahleho se benyang kapa se pinyehileng), konokono moo loop e koalang teng, the label — an unreadable figure cannot be matched to the pack it was cut for — and what the band has been lying in. Grit, mokgoahlapi, oli le metsi a emeng a tsamaea ho ea kopana, and a clean band is the cheapest protection available.

Protect the band from sharp edges, libaka tse chesang le li-welding spatter tse nang le letsoho kapa mosireletsi o kentsoeng. Ka holimo 100 °C, or where sparks are present, polyester is the wrong fibre and an letjeketjane le sa feleng with a heat resistant cover is the article to discuss.

One way or returnable: the arithmetic

The commercial case is simple and it is arithmetic, not preference. A one way band costs less per unit than a returnable sling and carries no return freight, ha ho ngoliso ea tlhahlobo, no repair and no loss write-off — but it has to be counted correctly, because nothing comes back to cover a shortfall. Bala ho tloha paketeng, eseng ho tswa ho tonnage: likhetho tse peli ka pakete ke lihlopha tse peli, a four point lift is four, ninety packs at two picks is 180 lihlopha. Add two to five per cent for the band cut while the pack is made up, kahoo khaello e fetoha mola holim'a taelo ho e-na le tieho boema-kepe.

Where the same slings are used week after week in one yard, a returnable article inspected between lifts is the cheaper order over a year. Where the sling leaves with the load — export packing, one off shipments, work that ends on a customer’s site, or a coated pipe consignment that is re-slung at the far end — the one way loop is the right purchase. Where the whole consignment travels as a netted unit instead of being slung joint by joint, a letlooa la ho phahamisa thepa is the article to price against it. The form with eyes at both ends, for loads that are hooked rather than wrapped, e ho tse lahlehang ka tsela enngwe leqephe; the wider family is on the likhoele tsa tšebeliso e le 'ngoe le single use lifting slings endless loop maqephe.

What to send with the enquiry

Six lines are enough to quote a made to order band, and they remove every ambiguity that shows up later at the load:

1. The load — pipe diameter and wall, bundle mass, or the finished item.
2. The pick positions — how many, and how far apart.
3. The arrangement — vertical, khangoa kapa seroto, and the angle if basket.
4. The girth at each pick, or the loop length with its convention named.
5. The safety factor your market works to, and the standard to mark to.
6. The reference to print, and the quantity per pack.

Lipotso tse botsoang khafetsa

What is a one way webbing sling?

A rated polyester webbing sling supplied for a single journey. E tsamaea le mojaro, is inspected once at the point of issue and is not recovered or re-issued. The endless form is a closed loop of flat woven polyester with no eye and no metal fitting, which is why it is the form chosen for pipe, tube and bundles.

Is a one way sling weaker than a reusable one?

Che. Fiber, loha, bophara, ntlha ya polokeho, working load limit and marking are specified exactly as for a returnable sling. The word describes the journey, not the grade, so a lower factor or a narrower band is not a saving on a single trip article.

Will a webbing sling scratch galvanised or anti-corrosion pipe?

The band is synthetic fibre and no shackle, hook or thimble touches the load when an endless loop is used, so there is nothing to cut or gouge a zinc, epoxy or polyethylene coating. Bophara ke tekanyo ea tšireletso: sephara se seholo, the lower the pressure at the contact.

How is the length of an endless webbing sling measured?

Two conventions are used and they differ by about a factor of two: selikalikoe sa sekoti se koetsoeng, 'me bolelele ba lebanta bo ne bo bataletse pele bo kopanya. Name the convention with the figure, or give the girth of the pipe or bundle the loop must go round.

Can the same loop be used in a choker hitch?

Ee, and a closed loop is the natural form for a choke on pipe, tube and bundles. Sebopeho se khangoeng ke 0.8 of the vertical working load limit, joalo a 5 t loop chokes 4 t. Select the width for the arrangement actually used.

Ke ntlha efe ea tšireletso eo ke lokelang ho e laela, 5:1, 6:1 kapa 7:1?

7:1 is the usual European figure for flat woven webbing slings to BS EN 1492-1, 5:1 is the customary North American figure under ASME B30.9, le 6:1 o dutse dipakeng tsa tsona. Tonnage e tšoanang ka ntlha e fapaneng ke sehlooho se fapaneng se nang le bophara bo fapaneng, kahoo ntlha ke ea patlisiso.

Na sehlopha se ka hatisoa ka litšupiso tsa rona?

Ee. Moeli oa mojaro o sebetsang, bolelele ba loop, ntlha ya polokeho, batch and your own pack, order or part number can be printed as produced, in the exact string you send, so a band at the far end can be tied back to a line on the packing list.