The short answer on EWP working height
Measure from the ground to the highest point your hands need to touch, then pick a machine above that figure. Then check outreach from where a truck can actually stand. Working height is about two metres more than where your feet end up.
Pick too small and you cannot finish the job. Pick too big and you cannot get it where it needs to stand. The mistake almost always comes from booking on one number when three of them matter.
Here is how to work out what you actually need, using the machines we run as the worked example.
EWP working height: three numbers, not one
Working height
The maximum height a person can reach to work. It assumes an operator standing in the basket with arms up, so it is roughly two metres more than where their feet are. This is the number quoted on every spec sheet.
Platform height
Where your feet actually stand at full extension. Always about two metres below working height. This is the number people get caught out by.
Outreach
How far sideways you can go from the machine’s centre. If you cannot park directly under the work, this decides the machine, not height.
Measure this way
From the ground, to the highest point your hands need to touch. Not to the top of the tree. Not to the ridge of the roof. To the work. Then add a margin and choose the machine above that number.
The towers we run
These are real machines in our own fleet, with real working heights. Where a figure is still being confirmed against the compliance plate, we have said so rather than published a number we have not verified.
| Machine | Working height | Typical use |
|---|---|---|
| GMJ LL22.350 | 23.5 m | The tall work. Transmission corridors, large mature trees, high building maintenance |
| Redmond Gary TF17M | 19 m | The workhorse height for distribution line work and street trees |
| Sherrin 18 m | 18 m | Similar envelope, different chassis and set-up footprint |
| Terex Hi-Ranger LT40 | 13.8 m | Tighter access, suburban street work, lower spans |
| Versalift SST-37 | 12.8 m | The compact end. Where access decides the machine rather than height |
| GMJ TT16 | Confirmed on request | Specification being verified against the compliance plate |
| Altec AT30-C | Confirmed on request | Specification being verified against the compliance plate |
A 23.5 metre machine that cannot get down the driveway is worth less than a 13.8 metre machine that can.
Access decides as much as height does
The taller the machine, the bigger the truck under it and the more room it needs to set its legs down. On a tight suburban block, or behind a standard gate, the constraint is usually not reach.
Gate and driveway width
Measure the narrowest point on the route in, not the widest.
Ground conditions
Stabiliser legs put a lot of load through a small footprint. Soft ground, recent trenching and anything over a void all matter.
Overhead on the way in
Low branches and low spans on the approach, not just over the work.
Where the truck can stand
Then measure outreach from there to the work. That is the real requirement.
When outreach beats height
If the work is over a fence, over a roof, across a garden bed or on the far side of something you cannot drive across, outreach is the number that decides whether the job is possible at all. A machine with more height and less outreach will get you higher and no closer.
Tell us the shape of the problem
Height, distance from where a truck can park, and what is in between. Those three sentences let us name the machine straight away. Without them anybody quoting is guessing, and the guess usually gets found out on the day.
The right size only helps if it is available
Working out the machine you need is the easy half. The harder half, on a lot of jobs, is that the machine you worked out is already on somebody else’s site for the next fortnight. That is where a size decision quietly turns into a scheduling decision, and it is usually what forces a crew onto a machine that is taller than the access allows or shorter than the work needs.
We run the fleet so that is not the answer you get. There is deliberately capacity held across the range rather than every tower committed to a long hire, because a new client asking for a 14 metre unit this week is not much use to anybody if the honest reply is a date in March. Sizing the job properly and then being told to take whatever is left is not sizing the job at all.
The same applies once you are on hire. If the tower you picked has to come away for any reason, another machine in the same size band goes out to you rather than the crew standing down or making do with the wrong one. That is what the size decision is actually worth: the machine you chose, on the job, for the length of the job.
Standards and inspection
Whatever height you end up with, the machine has to be a compliant one. The design and manufacture standard[1] governs how these machines are built, including the classification of insulated units, and the safe-use standard[2] sets out the inspection intervals and the periodic major inspection regime. Every machine we own is electrically tested every six months, inspected with the covers off every three months and load tested annually.
How to measure the job before you ring
Most jobs are specified from a guess made looking upwards, and that guess is nearly always low.
The reliable method is to find something of known height nearby and count off it. A single-storey eaveline is roughly 3 metres, a double-storey roughly 6, and a standard power pole gives you another usable reference. Count how many of those the work sits above and add a margin.
Then decide what you are measuring to. If you need to stand level with a gutter, the gutter height is your number. If you need to be above a limb to cut down through it, your number is higher than the limb. If you are working on top of something, you need to be above it, not level with it.
The margin matters. An EWP working height figure is the maximum the machine reaches with everything extended, in ideal conditions, on level ground. Specifying a job to the exact limit of a machine leaves you nothing for the ground being uneven, the truck standing further back than planned, or the work turning out to be a metre higher than it looked.
A metre or two of headroom costs nothing at the quoting stage and saves the job on the day.
Working height, platform height and boom length
Three figures, routinely quoted as though they were interchangeable, and each answers a different question.
Platform height, sometimes called height to the floor of the basket, is where your feet get to. Working height is conventionally that figure plus roughly two metres for a person standing in the basket, and it is the number brochures lead with because it is the biggest. Boom length is the physical length of the boom itself.
The Redmond Gary TF17M shows the gap plainly: 19 metres working height, 17 metres to the floor of the basket. Same machine, two metres apart, and if you specified a job at 19 metres expecting your feet to be there, you are two metres short.
Boom length matters for a different reason again. It is the figure the high risk work licence threshold is measured against, at eleven metres, so a machine can sit above the threshold on boom length while its EWP working height figure suggests something else entirely.
When a number is quoted at you, ask which of the three it is.
Basket capacity is the number that catches people
Height gets all the attention and capacity is what actually stops work.
The safe working load covers everything that goes up: the people, their tools, their harnesses, and anything they cut, remove or carry back down. Two people in heavy gear are most of the way through a 250 kg limit before anything else goes in the basket.
Across the fleet those figures range from 181 kg up to 350 kg, and the difference decides whether a job runs with one person or two. On tree work in particular, what comes down matters as much as what goes up.
It is worth being honest about this at the quoting stage. A machine chosen on height alone, with a basket that will not take two people and a saw, is the wrong machine no matter how far it reaches.
Wind, incline and the limits that apply on the day
Every published figure assumes conditions, and the conditions are on the plate.
The GMJ LL22.350 specifies a maximum operating incline of five degrees and a maximum wind speed of 12.5 metres per second. The GMJ TT16.300 carries a maximum windspeed of 15 metres per second. These are not guidance. A machine set up outside them is outside its certification.
Wind is the one that catches people out, because it is fine at ground level and considerably stronger at 20 metres. It also matters more with anything large in the basket, and on tree work a limb being handled acts like a sail.
Ground slope is the other. Jacklegs level the machine within a range, and beyond that range the machine will not set up. Identifying a sloping set-up point before the truck arrives is a five-minute conversation; discovering it on the day costs the morning.
Why oversizing costs you
The instinct once all this is understood is to take the biggest machine available. That is usually the wrong call too.
Bigger machines are wider set up, need more room for their jacklegs, weigh more on the ground, and cost more to hire. A 23.5-metre tower squeezed onto a suburban block to do 12 metres of work is a machine that may not fit down the side, may not be able to set its legs, and is being paid for at a rate the job did not need.
The right machine is the smallest one that reaches the work with a sensible margin, gets into the access, and carries what has to go in the basket.
That is a judgement rather than a formula, and it is the reason we ask about the site rather than just the height. Tell us the job and we will tell you the tower.
Matching the job to the machine
Working heights below come from the compliance plates rather than brochures. Where a manufacturer does not publish an outreach or capacity figure, it is shown as on request rather than estimated.
| Machine | Working height | Outreach | Basket capacity |
|---|---|---|---|
| Versalift SST-37 | 12.8 m | 8.5 m | On request |
| Terex Hi-Ranger LT40 | 13.8 m | 9 m | 181 kg |
| GMJ TT16.300 | 17.5 m | On request | 250 kg |
| Sherrin 18 m | 18 m | 11.1 m | 350 kg |
| Redmond Gary TF17M | 19 m | 13 m | 250 kg or 325 kg |
| GMJ LL22.350 | 23.5 m | 13 m | 350 kg |
| Altec AT30C | On request | On request | On request |
What an EWP working height figure does not tell you
It does not tell you whether the machine can get to where it needs to stand. It does not tell you how far out it can reach once it is there. It does not tell you what you can carry up. And it does not tell you whether the machine is rated for anything live nearby.
Those four things decide more jobs than height does, which is why a booking made on a single number so often comes unstuck.
Give us the height, the standback, the access at its tightest point, the basket load and the voltage of anything nearby. Five answers, and the right machine is usually obvious from them.
And if nothing in the fleet suits, we will tell you that rather than send something that nearly does.
Checking the figure against the plate, not the brochure
One habit worth adopting: treat the compliance plate as the source and everything else as a claim about it.
We have had that exact situation on our own fleet. A GMJ LL22.350 carries a plate reading 23.5 metres, and earlier copy in circulation said 24. Half a metre sounds trivial until a job is specified to the limit, and the plate is what stands.
So when an EWP working height is quoted to you, ask what it is quoted from. A figure off a plate is a certified statement about that specific machine, including its year of manufacture and its insulation level. A figure off a brochure describes a model, and models are built in variants across decades.
Ask for a photograph of the plate if you are planning a job around a machine you have not seen. It takes a minute and it settles the EWP working height question, the capacity question and the insulation question at the same time.
Which machine suits which job
Every tower in our fleet is an insulated EWP, so the question is never which one is better. It is which one carries what your job needs. Three figures decide it — working height, outreach and basket capacity — and a fourth, the insulation rating and the conditions it holds in, decides whether the machine can be near the line at all.
Working heights below come off the compliance plates rather than brochures. Where a manufacturer does not publish a figure it is shown as on request rather than estimated, because a made-up spec on a hire page is a safety problem rather than a cosmetic one.
The tallest tower we run, and the one that goes out when nothing shorter will reach — 13 metres of outreach still intact at full height, on a basket that takes two people and what they bring down.
Rated 132 kV dry, wet and in precipitation, which is the rating that matters when the job does not stop because the weather turned. Long outreach for its height.
A Glove & Barrier build on a 350 kg basket. The one to ask about when the work is close-quarters on live gear rather than simply near it.
A mid-height tower that gets into ground the bigger machines cannot. Ask us for the plate figures against your specific job rather than working off a brochure.
Compact and quick to set up, rated ANSI Category C under A92.2. Suits tight residential access where a full-size tower simply will not fit.
Low travel height, which is what gets it under a carpark header or a low branch line. Insulation is fitted as an option, so confirm it before the job is booked.
A compact telescopic tower. We publish figures off the compliance plate rather than the brochure, so ask us and we will send the plate for the unit going to your job.
Every tower above travels to Melbourne, Geelong, Ballarat, Bendigo, Shepparton and Gippsland — driven to site under its own power, not floated in on a separate truck.
Which one to take when the forecast is against you
This separates the fleet more than height does, and it is the question people ask last.
An insulation rating holds under stated conditions. Most insulated towers carry a rating for clean, dry conditions and a lower one for wet. The Redmond Gary TF17M is the one certified across dry, wet and precipitation at 132 kV, which is why it is the machine that goes out when rain is forecast and the work cannot wait.
That is not a mark against the others — it is what that particular machine has. For everything else in the fleet the rated conditions are on the plate, and the practical answer is to tell us the job and the forecast and we will tell you which tower is rated for it. We would far rather have that conversation on the phone than have you find out on the day.
Two things do not change with the weather: the six-monthly electrical test that confirms the machine is safe to be working with and around live power lines, and the fact that a replacement tower comes out if yours has to leave you.
Tree work near the line, and work on the line
Nearly everything our towers go out on is one of two jobs, and they pull in different directions.
Tree work near a live service is about reach and what comes down. You are standing off the conductor and working over or around it, so outreach matters more than raw height, and basket capacity matters because limbs come back with you. The GMJ LL22.350 and the Sherrin 18 m both carry 350 kg for exactly that reason.
Work on the line itself is about the insulation rating and the conditions, and often about getting into a tighter spot at a lower height. That is where the Terex Hi-Ranger LT40 earns its place — a light Class 5 chassis with a fibreglass boom that goes where a bigger truck cannot.
We are arborists as well as machine specialists, and the towers are out on our own tree jobs every day. That is why the fleet is shaped the way it is rather than standardised on one model.
Whatever you call it — insulated EWP hire, travel tower hire, cherry picker hire, a bucket truck, a boom lift or a man lift — describe the job and we will match the machine to it.
Insulated EWP hire across Victoria
Every tower is a truck, so it drives to you under its own power and sets up on its own legs. There is no float to book and no crane at either end, which is why distance behaves differently for us than it does for hire companies working off floated plant.
We hire right across Victoria. Beyond the towns above we run into Dandenong and the outer east, right through Gippsland where we are based, and up into the north-east — the Wangaratta and Wodonga side of the state is no trouble at all, we are over that way regularly. If your job is somewhere not listed here it is almost certainly still covered: insulated EWP hire across Victoria.
Tell us the job. We will tell you the tower.
Wet hire or dry hire, anywhere in Victoria, with a replacement machine behind it from the first day.
Frequently asked questions
What is the difference between working height and platform height?
What is the maximum height an EWP can reach?
How do I work out what height I need?
What is outreach and why does it matter?
Is a bigger machine always better?
What if I am not sure which size I need?
What is the difference between working height and platform height?
How do I estimate the height of my job?
Should I just book the biggest machine available?
What happens if the job turns out higher than I thought?
Does wind stop the machine working?
How much can I put in the basket?
Can the machine set up on a slope?
Does more working height mean more outreach?
Where does the working height figure come from?
Can I see the plate before I book?
Read next
Valley Wide Tree Services / 1800 GO TREES
Insulated EWP hire, Victoria
We run and maintain our own fleet of insulated elevating work platforms from a workshop in the Latrobe Valley, and we have been putting machines on Victorian jobs for years. Everything here is written from running them, not from a brochure.
Sources & references
- Standards Australia — AS 1418.10, Cranes, hoists and winches: elevating work platforms: The design and manufacture standard for elevating work platforms, including the classification of insulated units.
- Standards Australia — AS 2550.10, Cranes, hoists and winches: safe use of elevating work platforms: The standard covering inspection intervals, operator requirements and the periodic major inspection regime that a hire fleet’s service schedule is built on.
- WorkSafe Victoria — Elevating work platforms: The Victorian regulator’s guidance on selecting, setting up and operating an EWP, including the duties that sit with whoever controls the workplace.
- WorkSafe Victoria — Safe work practices using elevating work platforms: The regulator’s practical guidance note. States that a boom-type EWP with a boom length over 11 metres requires the operator to hold a high risk work licence.
- Elevating Work Platform Association of Australia: The national industry association for elevating work platforms, and the body behind the Yellow Card operator familiarisation programme.
General information only, current at the time of writing. Requirements change and every site is different. Confirm the rules that apply to your job with the relevant authority and with whoever controls the workplace before work starts.
