This weekend #engineering talk on....cranes! Cranes are used widely however they are generally used for lifting heavy/awkward things, so their use is strictly controlled & planned to ensure it all happens safely 1/ Image
Lifting operations in the UK are legislated by the Lifting Operations & Lifting Equipment Regulations 1998 - this is a UK law that governs how lifts are carried out, and places legal requirements on suppliers of cranes & those planning lifts 2/
LOLER has two main requirements 1) that the lifting equipment is safe for use, and 2) that the lift is planned & managed by competent persons 3/
1- Lifting equipment such as lifting tackle (chains, slings, hooks, shackles) must be thoroughly inspected every 6 months. Cranes, lifts that lift people (e.g manriding baskets) must be inspected every 6 months. Otherwise, cranes are thoroughly examined every 12 months 4/
That means that the lift in your apartment building or shopping centre is taken to bits and thoroughly examined every 6 months, including all rope, pulleys, sheaves, hooks, shackles & chains! This is all to prevent accidents and make sure everything is safe for use! 5/
2- "competent person" means you know what you're doing. People planning lifts are generally called the "Appointed Person (AP)" for the lift, and people supervising called "Crane/Lift Supervisors". Slinger/Signallers attached the chains and tell the crane driver where to go 6/
All these roles are legally specified although the terminology may differ. Again, this is to ensure only people properly knowledgeable, experienced and qualified are involved in lifts to keep everything safe. You can google 'lifts gone wrong' to see what happens... 7/
Cranes terminology as per diagram below: The slew ring is the centre of the turntable, also the base point of the boom (long extendable stick thingy) - jib is end of the boom the hook & rope dangles from) - outriggers stick out to keep the crane stable 8/ Image
Some basic maths: Moment = load x distance. The load is weight of what we're lifting. Distance is the radius, horizontal distance from centre of slew ring to centre of load/hook block/jib. The moment is rotating force that wants to make the crane tip over. 9/ Image
Therefore a great load or distance (the boom being further out) means a greater load. So the smaller the radius, the great load a crane can lift. The crane manufacturers publish charts that show this. See how load capacity decreases as radius increases 10/ Image
So all that load x distance is putting large load on the crane, and the crane sits on the ground. This is called the bearing pressure of crane on the ground. Pressure = force/area. So the crane uses outriggers (stabilisers) to increase/spread area of crane to reduce pressure 11/
The outriggers can then sit on mats to further increase the area and spread the load - this is a 1000t crane (max capacity crane can lift) and the outrigger mats are 5m long and needed a separate crane to lift them into position! 12/ Image
Cranes come in all shapes and sizes - an excavator can be used as a crane - did you know over 50% of excavators are used more lifting than for digging? This is a 25t excavator lifting in a formwork shutter (regular readers should recognise the location) 13/ Image
Some cranes are static, some are mobile, some can do 'pick & carry duties' i.e they can lift a load and travel with it - crawler cranes are great for this. They don't have outriggers because the crawler tracks spread the load widely instead. Here's a 60t crawler for piling 14/ Image
Here's two cranes working on the Girton bridge on the A14 - an 80t crawler and a 60t mobile. See the small round nylon mats on the mobile crane (yellow)! The boom was nearly 100m long on the crawler (in blue). Ground all built solidly to ensure cranes don't topple over! 15/ ImageImage
50t mobile crane lifting in a new gantry for an exit sliproad. The lifting 'tackle' is the upside-down V-shape slings connecting the hook block to specially-designed & manufactured lift points on top of the gantry, in case the gantry needs to be removed in the future 16/ ImageImage
500t crane lifting in a superspan Smart Motorway gantry. The 500t crane is so big it takes 3hrs to rig (set-up) and needed a 40t auxiliary crane to lift the mats and counterweight/ballast! 17/ ImageImage
Same gantry - look at the bend in the boom! This is normal, it's made from metal, and metal flexes, but very unnerving to see...😅 the 50t is small enough to self-rig itself and doesn't need any help. 18/ Image
More big cranes, here the large crane (in red) is lifting the main beam which is 35m in length and fabricated in Nottingham, meanwhile the auxiliary crane (yellow) is preparing the smaller transverse beams to be lifted. Careful coordination when 2 cranes this close! 19/ ImageImage
Ok I'm spoiling you guys now - 150t, 180t, 50t, lifting in beams & shutters of various sizes for bridges. The slings (bright orange) are hundreds of steel strands wrapped in nylon protective bagging to stops them getting damaged by rubbing/catching on things 20/ ImageImageImageImage
Here's the Baldwins 1000t again - this took a full day to rig, and was lifting a pair of beams at a time across the M1. Uses a lattice boom (like a mini-truss) because we all know triangles are stronger. Red light to warn aircraft due to nearby busy airport! 21/ ImageImageImageImage
This is a mobile all-terrain crane called a MERLO - similar principle to a telehandler but has a winch so can lift tings up and down - outriggers go out in under 60 seconds and can carry pallets on forks or use winch to lift things. Very expensive, but worth it, great bit of kit. Image
180t crane lifting in a Warren truss single-span footbridge - a common design also seen on roads like the A46 Newark-Widmerpool. Footbridges made in Kent. 22/ ImageImageImage
You can even set up cranes ON bridges! This was used to remove a temporary access to allow all of the brick cladding to be done over a live canal. A wide load required a lifting beam to spread the chains wider, they should never be more than 0-30degrees. 23/ ImageImage
Here's an extract of the Lift Plan - doc detailing the lift, specifying all the factors & loads I've previously mentioned. This crane used two setups hence two crane positions shown on Plan view. 78% capacity (load divided by capacity, generally 80% or less is safe) 24/ ImageImage
Biggest crane in the world, the 5000t-behemoth that is Big Carl, is in Somerset currently, working on the new nuclear power station at Hinckley Point C. Look at the size of the counterweight (to stop him toppling over), on a superlift tray 25/

bbc.co.uk/news/uk-englan…
The pictures from Hinkley Point C are insane, I can't even count how many tower cranes there are there and I'd hate to be the crane supervisor for that site - the 1st pic looks like a futuristic space port! (pictures sarens.com/about/news/wor…) 26/ ImageImage
I'm talking cranes this weekend because I'm lifting in bridge beams on the first half of my latest bridge, expect plenty of behind-the-scenes pics throughout the week! If you aren't already following, @Katie_Cranes is a prominent crane op in Twitter. Hope you enjoyed ENDS/
@threadreaderapp unroll please

• • •

Missing some Tweet in this thread? You can try to force a refresh
 

Keep Current with Alex Romankiw

Alex Romankiw Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!

PDF

Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @russiankiwi3

2 Dec
Bike is back from repairs so it's time for a Leicester city cycle tour, first one in a while. Also first winter ride of my adult life I think! The gloves went back in the bag after the first hill however.
#leicester #cycling #cycleinfra #ActiveTravel Image
This is the A563/A5630 Anstey Lane rbt. Despite Leics CC recently upgrading it, only one arm is signalised although the cycle route crosses at least two. 3 lanes of busy traffic on each arm. Less confident or mobile users have absolutely no chance. ImageImageImage
Towards Strasbourg Dr the path goes behind the bund. Like most New Town developments more land was used to futureproof the ring road. Now it makes a reasonable path along with 70s segregated track heading into the estate ImageImageImage
Read 15 tweets
30 Oct
Ooh shiny! Another bridge opening this week, Pooley Bridge in Cumbria, replacing an 18th-century stone arch bridge that was washed away by Storm Desmond in 2015. The new bridge features an interesting construction detail (image: newsandstar.co.uk/news/18818020.…) 1/ Image
The bridge is the first highways bridge in the UK to use structural stainless steel! To avoid the new bridge being washed away again, no piers in the river were permitted, so the bridge needed to span 40m - and also needed to be built over winter to avoid the tourist season 2/ Image
To be built over winter required an efficient design to permit speedy construction. Ordinary structural steel would be too heavy to lift the bridge in one span, it would have to be split into two halves requiring a temporary pier (and piers were banned by the Environment Agency)
Read 5 tweets
23 Oct
Some recent discussion has prompted me to do a quick thread on some UK road gantries (Disclaimer: Not A Designer). You may have noticed the latest road gantries have different designs and look bigger, & bulkier, than previous designs 1/ #roads #motorway #gantry #construction Image
Pic 1 is of a cantilever MS4 (large square matrix display) gantry, has been around for 10yrs+, it looks very sleek, slender and unobtrusive - contrast to pic 2, also for an MS4, which looks far bigger and bulkier 2/ ImageImage
The main reason is the tech - old 1980s road gantries were designed as accessible - there's a ladder access on the left gantry leg - to allow maintenance. However they didn't really get used except for by trespassers to unfold banners from (Remember the M1 in 2016 anyone?)3/ Image
Read 24 tweets
16 Aug
I've had some time to digest the recently-released Leicester City Street Design Guide, thread 1/: #leicester #cycleinfra #streets leicester.gov.uk/media/186708/l…
Streets are often our first interaction with the built environment, its what you step out into when you leave your building. Streets can make or break a nice place to live, and form many functions - providing some open space, allowing transport, and carrying utilities to homes 2/
Thanks to various planning changes and desperate developers, many modern streets are flawed - being uninviting for users, difficult to navigate especially for the more vulnerable, failing to promote active travel or a healthy lifestyle, and with high maintenance costs 3/
Read 27 tweets
8 Feb
Lots of angry people in Nottingham currently due to delays caused by the #A52 #CliftonBridge emergency closure over the River Trent, so a quick thread to help explain why these sorts of things happen (and why we can expect more of them) 1/ Image
There are two bridges over the Trent at Clifton; the west bridge (on left in photo) opened in 1958. The east bridge (closed) opened in 1972. It is an unusual arrangement in that on the northbound A52, the lanes split with lane 1 using the west bridge & lane 2 using the east! 2/ Image
The west bridge is made of post-tensioned concrete and due to its age was strengthened in the late 90s due to over 25% of the tendons being corroded. Put simply, tendons are long steel strands fixed under tension to pull the bridge together 3/
Read 21 tweets

Did Thread Reader help you today?

Support us! We are indie developers!


This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Too expensive? Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal Become our Patreon

Thank you for your support!

Follow Us on Twitter!