Official crane signals – Australia:
All Terrain Mobile Cranes
Operators’ Guides, Tips and Tricks
To all my readers: please be advised that all information in this article is an unofficial information and guide, and no part of the book or it’s writer or publisher can be made responsible for any action of any person that occurs as direct or indirect result of reading material provided in this book – if you don’t agree, please don’t read the contents!
In this book you will find information about on-road driving, setting up and operating of all-terrain mobile cranes ( up to 500t) that is derived purely out of personal experience over last 25 years of operating cranes in different countries and under different rules and conditions. No part of this article has any copy-paste text from anywhere. It is unique content written by me.
We will stick to the “plain English” and be straight to the point.
The aim is to save time and trouble to future, new and intermediate mobile crane operators by sharing experience – rather than having to learn out of situations that could spell disaster.
It is always good to learn from mistakes, as long as they are someone else’s previously made mistakes!
Assuming you know the basics of the mobile crane you are about to drive and operate, we will touch on all aspects of crane operator’s typical working day.
Any misconceptions and further questions can be directed to our online support group, whose address you can find within this website.
On road travel
To start with, it is true to say: “If the crane is ready for road travel, you are half way there!”
Pre-start check is mandatory but we all tend to just check the engine oil or simply turn the key! We are wrong.
It is not about “my boss won’t pay me 10 minutes for check-up”, it is more about being on time on the job or even worse – having avoided an potential accident.
It is always up to you, but this has worked for me: If I was the last one to drive it and I am positive that no one has tampered with it, I know if I need to check oils, coolant, belts etc. But in every case, I always check for any obvious horseplay (if someone has tried to be funny and make joke by setting me up with something) and walk right around the crane at least once, checking outrigger pins, tyres, lights and everything that is on the deck and might have chance to fall off while driving on the road.
Plan your trip in advance – some roads carry restrictions, some streets are one way the opposite way etc. It is not always easy to find somewhere to stop or turn around. Low overhead bridges and low limit bridges are especially dangerous obstacles.
Once engine is running normally, air is up to its working pressure, check one more time your mirrors, tip of boom and fly jib (if fitted) for clearance of any obstacles like nearby building, parked vehicles etc.
Quick glimpse over all instruments will give you immediate indication if something is wrong or left switched on etc.
Check your leveling position, independent rear steering is locked and the crane is all set for Road Travel. That might also include checking for high-low range of gearbox setting, control key setting (Krupp,Terex-Demag,Grove) and gear shifting preference. In general, “power” option is preferred by operators as most cranes are sluggish on accelerating, but crane does use a lot more fuel if this option is selected.
On the other hand, if driving in hills is anticipated, then “power” is the recommended gear shifting option as it prevents overheating and damaging the engine, utilizing more power out of it.
If starting to drive out of a tight spot where crane was parked, consider tail swing if the rear axle steers the opposite way (4+ axles all terrain cranes do). Also bear in mind the 2nd winch rear projection, if fitted with one.
If driving crane on the road with boom in the dolly, make sure that correct leveling procedures and requirements are met prior to driving, as it (overall level of the crane and the dolly) affects wheel alignment and line of travel, affecting steering and increasing tyre wear etc.
Usually, the best leveling for on-road travel with the boom in the dolly is achieved by leveling crane with dolly brakes OFF, on a firm level surface. This is only needed if crane is far out of level, otherwise normal “all brakes ON” leveling procedure should be good enough. Dolly brakes should be independently released out of the carrier driver’s cabin for this procedure. The best bet is to read manufacturer’s instructions and ask other operator or technician/mechanic.
Most all terrain cranes are equipped with additional braking system, electro-magnetic retarder.
It is usually mounted just in front of rear axle and it works on rear axle only. There are some things that driver needs to keep in mind about this type of brakes.
Retarder can act very powerfully and cause more harm than good. If used correctly, it saves normal brake pads and wheel drums, prevents brakes from overheating and keeps them ready for use in emergency.
It should be applied gradually and on time, releasing on time – just before coming to a full stop. First “click” of the retarder brake usually activates exhaust brake as well, so it must be switched off at the full stop of the vehicle.
If used suddenly with full power, especially on a wet or otherwise slippery surface, it almost certainly blocks rear axle – which can cause loss of control over vehicle.
If used for a prolonged period of time on a long descent, it can heat up severely and create fire hazard. For this, please read carefully manufacturer’s instructions and follow them.
Vehicle should never come to a full stop at the end of a steep descent if retarder was not deactivated on time earlier and given time to cool off!
Another potentially dangerous situation can happen if driving crane with boom in dolly and activate retarder on full power, not combined with main brakes; as the dolly will push onto the crane un-braked and the boom is in free slew; think of a high-speed scenario in a sharp bend with the road sloping towards the outside!!
Be clever – get info on it and use it correctly, it will be your preferred braking system.
Arriving on site and setting up the crane for work
If not familiar with the job site, it is always good idea to stop outside, on the road, and go for a look. It could save you a lot of trouble later, you could have to drive out and turn around or you could fall through a suspended slab!!!
You are the operator, so it is all up to you now. Everyone is looking at you and expecting you to make the right decision on setting up. For bigger cranes, this is usually pre-engineered and drawings of full set up and lifting scenarios are readily available, but not always.
Good set up is half the job done!
Look – look around and pay attention to everything you see. Everything is your potential obstacle and you will have to either remove it or work around it. Not only power lines, underground services and trenches, but also seemingly harmless things like the very bitumen driveway, for example. Some are very thin and made on a soft, not compacted ground; not asking about this could see your customer taking you to court for damages to the driveway, for example.
When estimating required space for set up, keep the picture of your crane in mind:
does the counterweight project past the outrigger line and how much (can you slew 360 deg freely?); is your second winch protruding even more; can you have the main working direction over rear, if using crane with one engine – can your operator’s cabins door face away from exhaust; are you going to block your exit with the material you place near the crane; if counterweights are coming on trucks – can you reach furthers counterweight if need to lift over front for set up; if you need to put the fly on – can you swing it in that direction, is the exhaust or something else going to be in your way;
If you need to set the crane up on a steep hill, the rule is for a front of crane to be facing down hill, if possible. This is why: all cranes have maxi (or tri-stop) brakes fitted to the rear axle, but not always to the front axle of the crane. So if the crane is to be set up with front facing uphill, the moment you lift the last axle with the maxi brakes off the ground, you are relying solely on the grip of front outriggers to prevent the crane from rolling downhill, which is not always good enough, especially if the hill is very steep. Tyre chocks are not much help. Setting up with the front axle being the first off the ground lives you with the braked back axle being pushed hard into the ground, creating even better grip and preventing the crane from rolling uncontrollably.
The other reason is that 5 + axles cranes have the front outriggers mounted between 1st and 2nd axle; so if you are lifting the rear outriggers, the front axle (which is in front of front outriggers) is being lowered, requiring you to lift the front outriggers – not good if they are already too high, facing uphill. You will need to claim the back even more. But if this is a must and no other option is possible, then use all measures to ensure the crane doesn’t roll off, like: build a provisional ramp to reverse on, so you gain some height in the back and can build up support timber-pack or pads under your outriggers and require less claim; use wheel chocks on front axle, and even jam the brakes with something so they stay applied all time (check if outrigger control box allows operation after brakes are applied, not all cranes can do this); if need to claim even more, pack under all wheels as much as possible with solid timber, making sure it will be stable enough to bear the weight of crane, then add more to your pad and repeat the procedure.
If you are confident that the crane can withstand the slew out of level to ? degree after out-of-level set up, the lower side can be easily corrected with help of booms weight, in two ways: luffing/jibbing up to the maximum degree in the direction away from outrigger you need to take pressure off in order to lift it, or telescoping out and lowering the boom in the opposite direction. The first option is safer, as it will not get the crane to the balancing point – which is always dangerous. If planning to do this and your crane’s counterweight is already on, take that in consideration and if it has to be, take the counterweight off until you have the crane set up level.
Proper set up is half the job done!
Most important thing before you do first lift is correct computer setting.
160t crane has overturned by the operator simply forgetting to change setting and has worked of last setting, which was full outriggers and full counterweight; where in reality now he only had base plate and worked all day at short radius high up; but towards the end of the day the long reach lift came and he didn’t click on it. Crane didn’t stop because its computer has calculated full counterweight and he would’ve been good for the weight, if he really had full counterweight.
To prevent this without taking any chances, this is what has always worked for me: don’t try to enter the rigging or configuration code; rather check and change/confirm all of the options: outrigger length, number of wire parts in the hook block, amount of counterweight used, fly jib extension/inserts length if any installed, and the crane will choose its own code, then you can double-check that the code corresponds to the configuration. If needed, enter your slew/luff/hook end limit and stick to it; it is not embarrassing – it might save you and others.
If using short outriggers, use correct computer setting. If you choose to use full outriggers on lifting side and short on off-side and have ‘full’ outriggers setting in computer, alarm bells should be ringing in your mind at all time for many reasons:
– If short side outriggers can not support the weight of the crane superstructure with counterweight you have installed, the crane will topple over backwards once luffed-up over the side, I have seen it happen
– If you forget about it at a later time, you could come around with the load on hook that is safe for full-outriggers side but not for the short-outriggers side; you might not be able to stop the slew on time and the weight might pull the crane over; seen that happen too
– Your counterweight slewing radius is usually at least the width of fully extended outriggers, so you might struck a structure or a tree that might be in your way
Short outriggers are only choice sometimes, and that is a major headache as it creates a scenario where operator is standing between a rock and a hard place: do the job, but don’t lose machine or hurt someone. If using short outriggers and need to slew around with or without a load, the best bet is to have the crane level and stick to manufacturer’s recommendations. If this is not possible, then you have to know your boom’s balancing point – where the weight of the boom is neither pulling you down and forward nor pushing up and backward. You can test this with outriggers fully extended (prior to encountering need for short outriggers) and having the outriggers pads 4-5 inches off the ground, slewing and luffing and watching the change in level; or by having the slew pin and brake activated at 0 deg over front or rear and the crane on rubber, where you can watch the pressure change in tyres while luffing up/down; some operators develop feeling for level change while in the operators cabin. All this is only for slewing around with empty and retracted boom – no load; for any lifting the proper configuration and load chart should be observed. One careful exception is for the directions between the front left-right outriggers and back left-right outriggers, here you can push it to the full load chart, if your outriggers are firmly on the ground and the crane is level.
Talking outriggers – packing is always very important. Even on a very firm ground, if using Teflon (plastic) pads, timber packing should be used to protect pads from small rocks and other small hard things like bolts and nuts, nails, small metal pieces etc. damaging them as they press into the pad and can get lodged or even protrude through the thinner part of pad.
To work out the packing area size needed to support the crane, use the applicable formula if you choose, but common sense works also: for most common hardwood timber packing (100X200X1200 mm), on a firm level surface, use 3 parallel timbers as a minimum for cranes of up to 50t and 4 parallel between 50t and 100t crane capacity; any bigger crane should be always set up on 6 + 4 timbers across or ready made pads or steel plates.
Soft ground set up is totally different story again and we will look into that now separately, as it is a big problem in most cases.
I would not mention ground types for simple reason that not everyone’s opinion about ground is same, you be the judge.
Cranes smaller size can be fully successfully set up on any type of soft ground, as long as you have necessary timbers available. Size of support pad is most important, but you need to keep in mind a few other things as well.
It is immensely important to have stable outriggers and this I find one of more dangerous situations for a simple reason that the crane can overturn even while well on chart, lifting a lot less than what the limit is. To top it off, it would be hard to predict (if not set up properly) which way the crane will go; even your counterweight might pull you over if legs start sinking.
To start with, even getting the crane positioned in desired place on soft ground can be a problem, so you need to decide where exactly your crane needs to be, before you have a go. It can happen that you will not have a second chance as you might get stuck in mud.
For this, estimate your route, check for any underground services as that not only will get you bogged but also you are likely to make extensive damage to them (imagine braking fiber-optic cable!) and could jeopardize the whole job. Avoid pits, canals, trenches, pipes etc.
Once you have decided which way and where to, engage you all-wheel drive but not the diff-locks, keep this as a back up. Reason – you might need to make a turn and the ground might be too hard for wheels to slip and avoid damage to differentials (if this is not clear, read the “use of differential locks guide” in crane’s operating manual or on internet). You also might make it there just fine without the diff locks engaged, and it is always good to avoid using this option (diff locks). If you don’t make it there in one go, or if you need to adjust to the side, problems might arise. The more you move in same place, the deeper you get stuck, usually.
If you do get stuck and the crane doesn’t want to move any more, don’t keep trying and trying. You might cause more serious damage. It is not the end of the world, there is a way out of that too.
If bogged, first check that you can still use your outriggers, pull pads out and place some packing under. I know, towing is first thing you might think of, but not many vehicles are available in front of you and able to tow your crane. If you happen to have an excavator on hand, that might help. Check carefully where you will attach the towing equipment and what will you use for it (wire rope, chain, nylon sling), will it brake, will the crane withstand forces etc. Never tow another vehicle with your crane with automatic gearbox!!!
If towing is not an option, get ready for a bit of work. You will need to get your crane on outriggers. If the crane sank on one side only, get that side set up and elevated so you can get hard material under your wheels. If placing timers under the wheels to drive on, make sure they don’t kick up when you start driving on them and damage your hydraulic or air lines above, only then you’re in real trouble!
If you sink again as soon as you start driving or as soon as you come off the hard material, there is one more option. Purposely made timber mats. Basically, hardwood timber pieces are connected with wire rope to form a mat, something like window blinds but in a super heavy duty edition. They are dragged around with and excavator or put in place by another crane. Place mats in front of your crane and bridge the remaining ground with more hard material; now you can drive. The best way is to have at least 4 of these mats so you can have 2 in front of you while driving on another 2.
Once you have the crane in place and the ground is soft, explore your options first. See if you can organize steel plates, made up timber pads, or at least extra long timber sleepers. If you are only equipped with standard size timbers, your options are very limited.
If you are using steel plates and you have option to use 2 plates on one or more outriggers, to make the support area bigger, the correct way of placing them is to form “T”, overlapping with the top plate all the way to the outer edge of the bottom plate, where your outrigger will be placed in the middle of the joint. If plates placed parallel, you will need to make very good connection between the two with a third plate or with hardwood timbers. If this is not observed, you could cause the plates to sink right under your outrigger, ‘stand up’ and your outrigger will go straight through!!
If you are using timbers on soft ground, you need to be careful when building your support pad. No gaps between the timbers should be left, at all. At least two layers need to be used, so that bottom layer is fully connected via the top layer and utilized. Only best quality and hard timbers are to be used, no improvising!
Build your pad as wide as you can, with the outrigger jack right in the middle of it. On soft ground, bottom layer of timbers doesn’t necessarily need to be on level ground, as they will squash the surface of the ground and make it level. Once you apply outrigger pressure on the pad you have built, stop and reassess the situation, see what the reaction of the ground is.
If the whole pad is sinking to the half of bottom timbers thickness or less, it is all good. You will need to monitor it further throughout the work and different weight distribution and react accordingly (stop, assess, build wider or higher pad etc).
If the support pad starts sinking severely to one side, you need to stop and either pack wider and longer timbers under that side at least or make the whole pad bigger, if possible. It is not for sure that sinking will stop later and pad out of level is not good in any case. Keep squashing solid material and adding solid timbers until you are satisfied the pad is safe to work on. Keep monitoring it!
I personally had occasions where crane as small as 30t had to have 4 x 3m solid hardwood sleepers under each outrigger. Do what it takes, basically.
Leveling on outriggers and pressure equalizing
This is another very important step towards finalizing the set up. The aim is to have the crane set up on shortest outrigger stroke, just off the ground, level and with equal pressure on all 4 outriggers.
Before lifting the crane off the ground, we need to lock the suspension. It should be locked with carrier lowered as low as possible. Thing to keep in mind, while lowering the carrier, is that the outrigger beam(s) might come down onto the outrigger pad or it’s slider (the metal bracket for stowing the pad) and damage it. Easiest way to prevent this is to apply little pressure on outrigger whose pad is already touching timbers underneath it, or even all 4 if that’s the case. Now you can lower the carrier suspension all the way without any worries.
If the crane is grossly out of level, try to level the carrier a bit more by coming down as far as possible on higher side, then follow with the lower side only up to the (close to) level position. It will be easier to pack up later if you lock the suspension in this position, rather than the whole crane all the way down pushing on all 4 timber pads. Once you are happy with the carrier position, lock the suspension.
Many all terrain cranes now have auto-leveling function and it’s fairly accurate. However, I find that in most cases they tend to lift the crane too high up (need to keep the stroke short) and in some cases run out of stroke before achieving level position, when the starting point of auto-leveling is on a high side, for example.
It is far better if you take control over it. There are many different ways to level the crane, following is most basic and very simple way:
To begin with, all 4 outriggers need to be pushing down onto the pads with some small pressure, as said earlier. Next step is to bring the crane level side-to-side by extending outrigger jacks on lower side until level is reached, both at the same time. Then simply lift the lower part of the crane up (front or back, whichever is lower now) by extending both (pair of front or pair of back) outriggers at the same time to the level position.
Most cranes achieve equal pressure on outriggers by doing this. If you lift the crane too far up and want to come down a bit, it should be done by retracting outrigger jacks in pairs back and front at the time, as the crane is close to symmetric outrigger weight distribution side-to side but not front- to back, and hydraulic oil (same as everything else) tends to flow in the line of lesser resistance (higher pressures-where the heavier part of crane is- are released sooner and quicker), so you need to avoid getting out of level to far.
You might have to come down a bit more than your desired position and come back up again, in order to assure equal pressure on outriggers again. If you have pressure display available on the crane you are working on, front pair and rear pair of outriggers pressure reading should be as close to equal as possible, respectively.
It is hard to achieve this (correct operating pressures) by operating outrigger jacks one at the time. Always try to operate two outrigger jacks at the time (front and back in pairs).
Once you are happy with the set up, take another look, walk around, make sure all wheels are off the ground and you can slew 360 deg without hitting any obstacles or you are aware where they are and you can react accordingly and on time.
If you are using any additional counterweight, you are probably familiar with the procedure for the given machine and situation, only thing to mention is that in some cases it matters not to have the boom luffed up too far as it causes misalignment (even only minimal) and can cause some automated systems (ex. GMK 4100) to over-slew while getting into the centre position. Luff down to 65 degrees or so helps, slew becomes more controllable.
Programming crane’s computer
for the task is another crucial thing.
As mentioned earlier, be very careful with this. Enter the correct code or even better – let the computer choose it. Confirm visually that correct values are entered for outrigger length, counterweight amount, hook block configuration and slewing radius. If you have short outriggers on off-side and you are confident that you will do the task successfully by tricking the computer and entering the full amount of outriggers as you are indeed using the full length on working side, have some sort of reminder arranged so you don’t mess up by forgetting all about it after some hours of working!
Choosing the best boom configuration and suitable lifting gear are the next steps, try to think ahead and make it easier for yourself. You might not be able to reach your box with lifting gear later with long boom as you might not be able to luff up to it; get it (your chains etc) out while you have short boom available so you don’t waste your and client’s time by having to retract the boom later.
If working with the single telescoping cylinder, keep in mind that you can’t extend the light boom sections after you have the heavier boom sections extended, without retracting the heavy sections first. Whenever structurally safe to do so, choose light boom sections for your task. Having said that, keep in mind that, while saving you from tipping by being lighter, light boom sections can and DO bend/brake if severely overloaded! If unsure about this, follow manufacturer’s recommendations.
For telescoping, choose right boom angle – usually 75 degrees and more, so your boom sections don’t create too much friction on wear pads and grease doesn’t get scraped off so easily. If for any reason your anti-two block isn’t working and you have to have the override key engaged, keep looking up or simply keep the chains at your eyes level while telescoping, so your hook block doesn’t try to claim on top of your boom!
Slewing, luffing and winching
Often combined, all three operations are equally used and important.
For any and all of crane’s movements, remember: the movement is to be controlled by moving joystick (lever), not by changing engine’s speed/revs!!!
To make it a bit more clear – it is not right to displace joystick in any direction and then change the speed of function by changing the engine’s speed, as engine might stall in critical moment, and even if not – it is never accurate option.
The right way is to have the engine’s speed up and hydraulic oil pressure available before starting any function and keeping it at that. Most new operators have the initial coordination problem between hands and feet – to use them at the same time, but it is only temporary and the sooner you get onto it the sooner you will have it under control. Most cranes have the idle speed control available as aid to operator too and it is wise to use it when accuracy is needed, as it delivers constantly equal oil pressure and cranes movements can be done more smoothly and more accurately.
The only downfall is that the engine speed is wasted while not in use, unless you disengage the engine speed control.
Definitely better option is to use normal foot pedal accelerator control.
All but one crane functions fully depend on engine’s speed:
Luff-down in most all terrain cranes is achieved by free-falling the boom, after the pilot pressure is supplied to the luffing cylinder, which is normally between 60 and 100 bar (up to 1000 rpm). Any higher engine speed while luffing down will not make it quicker, so it is waste of fuel and a lot of noise for nothing.
This is not the case with boom-up movement, where the optimum power is required and if this is not observed, engine can easily become overloaded and stall. That usually happens when adding winch-up as the second movement to the boom-up, as both require a lot of power. To avoid this, stay tuned with your engine’s power, hydraulic oil pressure and even the sound of engine while operating.
Imagine, if you boom-up violently, load starts moving fast, you add the winch-up function and then the engine stalls, the load will continue to travel in swing motion – towards YOU!!! You will not have the option to change anything about it, not even to drop the load onto the ground.
If you follow correct operating procedure, no problems what so ever should ever occur.
The correct procedure for any movement is to start of slow and finish slow, while adjusting the speed of movement in between. Remember this. Even if you create minor swing after starting the movement, it is simple to catch it if you act on time; by slowing the motion down, letting the load to catch up with the head of the boom (90 degree upright, direct above) and starting the motion again at the now load’s speed. It will not be any slower if you do it this way; it will only be slower if you create larger swing by taking off too quick and/or stopping too sudden and being forced to catch the swing afterwards.
More experienced operators are not worried about the swing when the speed is appreciated – they take off in controllable manner, create swing by accelerating sharply but judging the end-point and catch the swing at the end. Having said that, keep in mind that here we are talking about known situation, with no obstacles and well known destination of the load. Catching the swing is very important part of operating the crane and everyone should practice this at the very beginning of the carrier.
Load swing in straight (to-and-away) motion is somewhat easy to manage and can be fun, the harder one is the circular swing. This should be controlled by transforming it into the one-way swing first and then catching that one (either slew or luff). If any of this is problem, just stop slowly somewhere safely and wait for it to slow down. Even if you only slow down to very slow speed and continue your motion/s, the swing is likely to stop completely.
For centering the hook above the load prior to pick up: while bringing your hook with chains or other lifting equipment down to the dogman or rigger/person in charge on the ground, look where that person is looking, following your hook with his eyes. That will give you good indication how close to being right above that person your hook is.
Once your chains are attached to the load, if you after taking all the slack out by winching up slowly but not taking the weight on, you will know if one chain or one pair of chains starts getting tension earlier – you need to reposition your centre, move your boom more in that direction. Keep in mind that this is only accurate for symmetric loads and if all chains or slings are exactly equal in length, with all additional equipment (shackles, nylons etc) and if ‘choking’ is used, all ‘bites’ are in same position.
Increase in radius caused by lifting a load is referred to as boom deflection. I personally don’t exactly agree with this definition as it is a result of flexing of the crane chassis, outriggers etc combined with boom flexing/bowing. Therefore, it is rather (crane) deflection. It must be always expected and accounted for, operator must know how to compensate for this as it can and often does make things hard. It can create dangerous situation. Try not to learn it the hard way.
The easiest way to keep tracking of this is too watch radius change while taking on the weight. You should always remember/mark exactly the starting radius and go from there.
Most crane computers are fairly accurate, to the 100mm tolerance. If you need more precise option, then pay attention to how long since your last radius change happen prior to taking any weight; for example: you are luffing-up, to 16.9m , 16.8m , 16.7m… slowly…, and a bit more…, and you stop. It was probably just about to change to 16.6m, so it is definitely more close to 16.6m than 16.7m. If you were luffing-up the same way and you have stopped as soon as 16.7m digit appeared, you are more on the 16.7m radius, very close to it. So, remember your radius starting point. It would be good if you could find out exact weight of the load too, you probably know it close enough in any case. It is important to know when you have the most of the load’s weight taken on and when the load will lift off the ground, as taking the weight is actual transfer of forces from load to the crane and it doesn’t happen instantly, your crane is taking it (the weight of load) over as you are winching/luffing up. Think of it as using the crane to defy the Earth’s gravity force to the amount of load’s weight. (9.81 m/sec square, times load’s weight).
Take all the slack out of your lifting gear by winching up and start taking the weight slowly while watching your radius closely. At very first increase of radius reading you should start luffing-up, releasing the winch motion. Degree of deflection varies greatly and is very hard to predict accurately, as it depends on many factors like the weight, amount and angle of boom used, counterweight etc. In general, the heavier the load and longer the boom, the more deflection is to be expected, basically.
While taking the load with the luff-up function now, pay attention to how close to the full weight you are getting and what your radius is. If the radius is increasing even more, you will need to compensate by lowering some winch wire while luffing-up.
If the radius is decreasing, you might need to stop the luff and winch-up until you reach the centre radius again. You should not let the radius change too far away from the starting value, as the load will swing when taken off the ground. Ideal is to lift of at exactly the same radius. Keep in mind your load’s weight and be more careful when approaching the lift-off point. Some loads you will want to lift on luff-up, some on winch or even winch-up and luff-down, maybe even combined with the slew.
There isn’t much more to it; if you follow this in controlled motions (not too quick and no sudden starts/stops) you will have no trouble getting the load off the ground without having it swing in either direction.
Strong winds represent great danger in crane industry as wind can destabilize the crane and cause it to overturn.
Effect of wind is equally dangerous on both lifted load and the crane’s boom, only it acts in different way.
Every all terrain mobile crane comes with the Operator’s Manual; in the manual, there is manufacturer’s recommendation for safe operations with different wind forces. There is information of how strong wind your crane can withstand in each different configuration before it has to be shut down and the boom retracted. That information is for the crane function without load only – the crane can still slew up-wind and the slew brake can be used.
Yes, wind can cause the crane not to be able to slew up-wind or to stop the slew safely. All other functions are unaffected. Slew function is most affected simply because of the very physics – how the crane is built: the whole length of boom acts as a giant lever against the slew motor down on the slew ring.
Load lifted, beside it’s weight, creates double effect: if the load is of a large wind collecting area, it can be pushed by wind in undesired direction and even become uncontrollable, start swinging violently in various directions and even do a major circular swing. On top of that, load is also pulling the crane’s boom, which is always dangerous. It can cause a major accident.
All modern cranes come with the wind meter, which is installed separately. While they give you exact measurements of wind speed and wind gusts, they can sometimes be more of a pain in the back side. For example, you could be working with small material bin and have virtually no load and no wind collecting surface to worry about, with winds way less than manageable; but if your wind meter is programmed to stop the crane at certain speed, then a short gust will see your crane’s movements be often interrupted and there’s little you can do about, except to use your override key (defeats the whole purpose).
It is up to you to try and decide to have it on or not, you will need to include some common sense and a bit of a gut feeling too.
In any case, wind is something that is to be taken seriously and all aspects of work to be undertaken are to be considered and thought through very carefully. Operator needs to make sure that every member of the load controlling crew knows exactly all possibilities and procedures in windy conditions – it could have catastrophic consequences if operator has to drop the load and the crew doesn’t expect that, or similar.
Fly Jib extension
When greater heights need to be reached, or greater radius with a smaller load, fly jib extension is installed on top of a hydraulic boom.
It is easy to find out from crane charts what option is best for given situation.
Be it fixed or luffing fly jib extension, operator needs to be trained on each different type of crane separately as they differ greatly and accidents while installing fly jib are happening all too often. All manufacturer’s recommendations are to be taken very seriously as extensive damage to the crane can be done very easily.
All movements need to be as smooth as possible and overloading absolutely avoided. It is absolutely critical to observe this, and all cranes have volume settings for operating with fly jib fitted. Some cranes also have the maximum power while fly jib fitted reduced to 70% or less.
Both tipping and structural damage to the boom and fly can very easily occur if too much overloading happens.
I wish you successful carrier.