spurs/pickups: tension & compression (1 Viewer)

paulscaff1

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I've posted this in the study group but it seems a bit quiet.

When using spurs to pick up a cantilever from above,

Am I right in saying that the spurs should be laced in compression ( doubles outside\inside)

And from below, laced in tension (doubles outside/outside)

Its just that it seems some scaffs seem put them on wherever is easiest, unless I'm wrong?
 
Surely, Rakers/spurs from above the supported lift would be under tension and picking up from below under compression? The Tubes & fittings. As for fittings outside or inside of the Aberdeen or bridal transom which ever is easiest/practicable given the constrainst of the job or habbits. Think a designer would say it makes no difference. Just put your checks on the right side! Think weve all seen a few jobs with checks doing bugger all
 
Yea the spurs from above would be in tension, there for they would be laced in compression so that its pulling back

---------- Post added at 10:24 PM ---------- Previous post was at 10:11 PM ----------

Probably doesn't matter either way, if it fits in the textbook way then I'll do it that way.

Often get questioned why I'm lacing it the way I do lol.
 
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Surely, Rakers/spurs from above the supported lift would be under tension and picking up from below under compression? The Tubes & fittings. As for fittings outside or inside of the Aberdeen or bridal transom which ever is easiest/practicable given the constrainst of the job or habbits. Think a designer would say it makes no difference. Just put your checks on the right side! Think6ger all

Thats wot i ment lol
 
Kind of the same thing when talking about plan bracing beams. Always inside to outside for compression I was taught.

Can alan reade confirm if it matters which way?
 
Complected malarky this old scaffolding game , now i have to worry about compression and tension and supplementary fittings :(
 
Lol phil its only taken me 30years to learn theyre called supplimentry couplers lol...think we'll just av to stick to our leaners m8.....

change of subject phil just got my 1st batch of scallops this year needed a lifting bag to get em up-paddled all the way back to the shore to find out the fcuking carabina broke & all i had was a goodie bag with no goodies init:(:(:(
 
haha, thats the street scaff in ya Phil.

so lacing spurs.is that like a wing brace:unsure::wondering:
 
Not sure if i understand you properly as you may use differnt terminoligy to us but if your talking about the spurs onto a bridle as a canterlever we would normally fix with the top fitting/dc up the right way hanging underneath the bridle,pointing outwards with the supplementry directly below stopping any slip -the bottom fitting would then be turned upside down so the gate rests into the ledger with the supplimentry on top stopping any push down
-if your talking about pull backs then we'd do it in reverse with the top fitting of the pullback upside down & the supplimentry above stopping this tube being pulled through the 1st fitting , the pullback going down to the bridle on the outside with the fitting the right way up & this time the check supplimentry on the opposite side underneth to stop any drop-hope that makes sense
 
Nice one nick exactly as i'd written it :) -a picture paints a thousand words lol
 
If nothing else, I thought it'd make a good conversation piece.
 
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Was thinking, spurs come from below, whats it called when supporting from above?? pullbacks doesnt sound very technical, unlike supplementary couplers.

---------- Post added at 08:42 AM ---------- Previous post was at 08:36 AM ----------

Lol phil its only taken me 30years to learn theyre called supplimentry couplers lol...think we'll just av to stick to our leaners m8.....

change of subject phil just got my 1st batch of scallops this year needed a lifting bag to get em up-paddled all the way back to the shore to find out the fcuking carabina broke & all i had was a goodie bag with no goodies init:(:(:(

Had to laugh at this one, done the same thing a while back. Where you getting your scallops from sp?
 
About 1/4 mile off shore between weymouth & durdle door the seabed drops down to abot 22/26m onto aperfect sand& shingle bottom-ideal for scalloping.i normally paddle out on a diveyak & tow it behind me when diving-saves a fortune on the local charter boats
 
Morning Guys
sorry late in on this post Nick has the answer in his sketch.
Compression is shortening a member and the supplementary and/or checks are applied to the inside whist tension is lengthening and the couplers are on the outside.

in general they both (compression & Tension) get to the same result but need to be considered with the individual application.

It is worth pointing out that a "supplementary coupler" (whilst it has the same basic result) is not the same as a "check coupler".
A "Supplementary coupler" is used when the capacity of a fitting is less than the load bearing capacity you are looking to achieve, example:
a double is worth say 6.1kN but the load to resist is 10kN you apply a supplementary coupler to achieve the load required.
A Check Coupler is a security back-up coupler, example:
The same double on a hanger is worth the same 6.1kN and the desired load is only 3kN but we apply the "Check Coupler" as security against the failure of the support fitting.
 
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