Friends of 42 Traverse Inc. are acutely aware of a need to maintain a good Health and Safety record.
Not only do we need to work to our own standards, we are also obliged to conform to the policies of the Department of Conservation (DOC) who have several documents detailing operating proceedures for activities such as machinery use.
The level of training and assessment required by DOC to operate a chainsaw is considerable and most volunteers are unlikely to make the investment of time and money to achieve the required DOC standard.
The use of bush/scrub bar machines is also regulated but much more achievable. A good machine with a sharp blade can manage to cut up to about 100 mm branches. DOC have provided the paperwork needed to get their approval to operate such a machine on land that they manage.
Scrub Cutter use
Scrub Cutter use.
(See also Scrubcutter Safety Manual, prepared by Stihl on olddm-567769.)
Only approved and competent operators may use this machine. Staff being trained must have close supervision by someone who has been approved and competent. A definition of an approved operator is someone who has completed the scrub cutter induction process, and has been signed off as competent to use the machines in the field by a person who has been assessed as ‘competent to assess others’ and this is recorded in DOCLearn. Areas that must be covered during an induction are:
If a person has obtained NZQA unit standard 24540 (maintain and use a brushcutter) this may be used as evidence of competence.
1. Correct fitting of Harness and techniques to avoid back strain
How to set up harness: put on harness and attach bar for weight. Weight to be balanced through shoulders straps, adjust height of connection hook through the side attachment so that bar is sitting on point of hip and running at about 30º angle across front of body
Correct stance: legs slightly apart – the taller you are, the further apart this will be; bend knees not waist, and move through full range of motion using legs and torso – torso to be almost solid from knees to shoulders; be aware of your stance (and that of others) throughout the working day; the correct stance becomes harder to maintain if you do not have some experience and there is more tendency as the day wears on to bend from waist and hunch the shoulders. With practice and perseverance it will become quite natural; use other methods listed here to maintain both mental and physical well-being.
2. Correct safety gear and it’s use
Steel capped boots are recommended, chaps for blade use (optional for flail), overalls (optional if wearing chaps), helmet with visor and muffs (grade 4 only so as to allow better peripheral hearing), if not using a visor, safety glasses or “fly eyes” (safety glasses with rubber straps are best, this negates any discomfort when wearing earmuffs), hi-viz vest /t-shirt (with good UV protection)
3. Correct fitting of tri-blades and Flail heads
4. Correct length of Flail to be used with Flail heads
Use the correct length of flail for flail heads if you are using non “self feed” type heads. Industrial scrub bars are designed to use a blade. Use only the flail head that comes with the scrub bar as recommended by the manufacturer. These heads will fit the safety guard and usually have an inbuilt auto trimming system.
5. Use of safety guard
Demonstrate. Use of a safety guard is mandatory. Fitting after market flail heads may render your safety guard ineffectual. If fitting an aftermarket head (non self feed variety or other) make sure the disc created by the spinning flail lines up at the centre of your safety guard.
6. Use of flail head
Several factors need to be understood to safely use a scrub bar with a flail head. These are as follows:
¨ Concentration levels must be high at all times. This means being aware when you are tired and when you need a rest or food or liquid intake
¨ Using the appropriate throttle control for the surface and material you are cutting i.e. where you are cutting soft vege amongst small stones and rocks use low rpm. Flail will still cut at low rpm and tilt your bar to minimise the amount of material that will come back at you (demonstrate)
¨ Most injuries using flail are deflective ones i.e. stones or twigs bouncing from the chest under the visor into the face. Make sure that when you are cutting areas where small stones and rocks are prevalent that you hold your chin slightly down. This makes the gap between visor and chest smaller
¨ Even at low rpm flail will form a clearly visible disc. Be aware of the edges of the disc when you cut and what portion of the disc you are cutting with i.e. am I cutting on the back hand or fore hand, do I have any tilt on the bar. All these factors will have an effect on how matter is thrown back towards you. Awareness is your best defence against injury
7. Vegetation types and sizes appropriate to blade and Flail
A lot of time, energy and money is wasted with people cutting inappropriate vege for whatever attachment they have on their bar (flail or blade) set teams up to reflect what they are actually cutting i.e. two with flail, one with blade or two on blades, one on flail etc and add a chainsaw if necessary . Then set cutting max sizes/diameters for flail and blade. Then it is a matter of everyone cutting the appropriate size material. The initial set up will take some time but once teams are in the swing and trust each other to do their job, the work will progress very quickly. Tired people tend to make mistakes
8. Techniques and desired range of motion with bar attached to correctly fitted harness
9. Appropriate Throttle control
Use the throttle intelligently. You do not drive a car with the gas pedal fully depressed all the time. You need to decelerate and brake as the road demands. It is no different when using a scrub bar.
10. Levels of concentration expected
The ability to maintain concentration is paramount for safe use of a scrub bar. Eat well, hydrate well and take regular breaks. Use the other methods mentioned in this SOP to help concentration levels
11. Risks of using blades in the back country and front country with guards fitted
Tri-blades are used as they are easy to sharpen and have a long life in amongst the rocks and stones of back country tracks. They also do not tend to break and chip as do “Chainsaw” blades and tungsten tipped “saw tooth” blades (these are dangerous in rough country where rocks are prevalent).
A guard must be fitted at all times. Note:
· The easiest and safest way to cut steep slopes in the back country is to back down them i.e. take a step backwards (watch where you are going), make sure your feet are firmly planted then start to cut. When you have cut what you can reach repeat the procedure. Do not overreach. Be aware that the guard in these circumstances can sometimes become a hindrance and will catch on roots and rock and this can put you off balance.
· Precision cutting is preferable to the bash technique that seems prevalent when most people get hold of a bar with a guard on. Control over the cut is the key to safety when using a bar and blade. In order to be precise you must be able to see what you are cutting and that allows you to cut once. The guard can hinder this ability to see so people have to feel their way and this is difficult if conditions are not optimum i.e. terrain is flat and even. Thus the bash approach ensues which is hard on staff and gear and produces a second rate job. If you second cut i.e. make one cut and then make a second cut to lower the stump then on the second cut the (tri) blade will tear the stump into pieces and fling debris back at the operator. Current rules do not allow for the removal of the guard so care must be taken at all times to “cut once”. take your time and think about what you are doing
· Remember to flip your blade regularly i.e. if cutting is heavy then flip blade every 1.5 to 2 hours. If cutting is light then once every 4 hour should be enough. Blades should be used so that they wear evenly on both sides this helps with sharpening and also helps to keep them balanced. Unbalanced blades are hard on machines and people.
12. Ideas on how to work in a team with bars
Team management techniques: when completing a vegetation cut on a track, for the majority of track (up to 1.2 metres wide) each person should work on both sides rather than only one. This will allow a full range of motion that will not occur if someone is working just one side of a track and in the long term will lessen fatigue and the incidents of cramping or strains. They will also “leapfrog” each other. Leapfrogging will allow team members to rest regularly as they cut. Plan prior the work for each team member to cut no more than 50m (max), i.e. second person to start 50m ahead, the third 100m etc, then when first person reaches the cut section ahead, walk until 50m ahead of the person at the head of the team and start cutting – this allows for regular breaks for stretching and relaxing as you walk to the next section to be cut and allows a mental rest break. Over particularly difficult terrain or where teams are predominantly inexperienced 20 or 30 metres may be more appropriate. Be aware that as the day wears on you will become tired and your technique and concentration levels drop. Take regular rest breaks and make sure your intake of food and drink is good. Glucose high foods are good for afternoon smokos
Where track is wider than 1.2 metres and it is easier for team members to cut just one side, make sure that teams swap sides every 50 metres or so to make sure strains and other such injuries are minimised
13. Expected performance levels
i. Standard safety equipment is to be worn at all times whilst operating this machine. These include helmet, ear muffs grade 4 and visor (safety glasses/fly eyes are optional under the visor or alternate options to a visor), safety boots are recommended but leather boots (good quality tramping boots) should be a minimum, hi-viz vest/t-shirt and a minimum of overalls. The use of chainsaw chaps to protect your legs is optional with flail only! Gloves are also optional.
ii. Any persons that are assisting with the operation but not using a scrub cutter must also wear approved hearing protection and a hi-vis vest. A helmet and visor is optional outside the 15 metre safety zone (ear muffs must still be worn).
iii. A minimum distance of 15 meters is to be observed at all times whilst the machine is in operation for all staff including those involved in clearing work. This does not include the distance between other operators. There will be occasion when one operator will catch another during work. It is the responsibility of the catching operator to assess the situation and judge whether it is safe to keep cutting or stop and wait. This will depend mainly on the surface being cut i.e. lots of stones etc. All operators should not be so involved in their work that they lose peripheral vision and hearing
iv. Appropriate signage is to be placed both in front and behind of the operators to ensure adequate warning is given to other track users that machinery is in operation (mainly front country use). Use also visual delineators (cones) to cordon off work area when appropriate/ needed. Exception to this is back country work only.
v. Flail to be used on vegetation up to 10mm diameter (depending on species of vege). Tri blade to used on vegetation up to 50mm diameter (depending on species of vege and blade), guard must be used.
vi. Use only cutting attachments and accessories that are approved for these scrub cutters. If you are unsure check with the D Band Ranger or the CSM.
vii. Carry out pre-operation tasks as noted in Appendix 1.
viii. Follow instructions in Appendix 2 when starting the scrub cutter.
ix. Carry out post operation maintenance as listed in Appendix 3.
x. Do not modify the machine or any of the accessories without discussing the proposal with the D-Band ranger or CSM and gaining approval for the task.
Training and Competency
Users must be assessed as competent to use. (Assessment form docdm-480263)
Districts are to ensure that they have experienced employee(s) who has been assessed as ‘competent to assess others’ and this is recorded in DOCLearn.
Pre Operation Checks:
1: Check the Angle Gear:
· Remove the Grease filler cap and check the grease level.
· Fill till about ¾ full with grease.
· Do not overfill
· Never use an unapproved or unlabeled grease
Use only Husqvarna/Stihl Angle Head Grease (half teaspoon every 6-8 hours of work is about right, overfilling will result in seals popping).
2: Check the fuel level:
· Remove the filler cap and check the level
· Refill the tank if the level is low
· Refill the tank in a well ventilated area.
· Never use any unlabeled or unapproved fuel mix.
Use only 50:1 mix that has been prepared and is labelled in the fuel store.
If mixing fuel use only Stihl 2 stroke oil at a 50:1 ratio (if unsure check with Ranger field C Band)
3: Check the Shaft:
· Ensure that the shaft is not bent or twisted
4: Check the lock nut:
· Ensure that the attachment that is on is securely attached and that the reverse thread lock nut is in good condition.
The reverse thread lock nuts should be replaced with a new one after every 15 uses. 1 use is taking it off and putting it back on. The old lock nut is to be thrown out.
5: Check the start stop switch:
· Ensure that the start stop switch moves easily between the two settings.
6: Check the throttle trigger:
· Ensure that the throttle trigger and throttle trigger interlock action is smooth. The throttle trigger must return automatically to the idle position.
7: Check the harness:
· Ensure that the harness is adjusted to suit your height.
8: Check the handles:
· Ensure that all the handles are dry and clean, free from oil and safe for control.
If a fault is noted in any of the pre operation checks D-Band Ranger or Workshop Manager must be notified immediately and the machine is not to be used until repairs are completed.
Starting the Scrub Cutter:
1: Start the engine at least 3 meters from the fuelling spot
2: Set the throttle control to the start position.
3: If the engine is cold engage the choke lever. If the scrub cutter has been running but is cold the choke is not required.
4: Press the machine body against the ground using your left hand.
Do not use your foot on the shaft and there is no need to use your whole body weight to hold the machine down when you start it!
5: Ensure that the cutting attachment is clear of any obstacles on the ground.
6: Grip the starter handle, slowly pull out the cord with your right hand until you feel some resistance. Now quickly pull the cord. Do not pull the cord out till it stops; this is a great way to break starter cord. Short sharp pulls inside the full range of motion are best
When the engine is started with the choke in, the choke or start position the cutting equipment starts to rotate immediately.
7: Do not pull the starter cord out completely and do not release the starter cord from the fully extended position. This will damage the starting mechanism.
8: Do not under any circumstance drop start the machine. This will cause damage to the internal components of the starter system.
9: Reset the choke control as soon as the engine fires and repeat until the engine starts.
10: When the engine starts quickly apply full throttle and the start throttle will automatically disengage.
11: Note that the cutting tool continues to rotate for a short period after you let go of the throttle trigger. This is called the fly wheel effect.
12: Check the idle speed. The cutting tool must not rotate when the engine is idling with the throttle trigger released.
Do not adjust the idle yourself!
If a fault is noted during starting the D-Band Ranger or Workshop Manager must be notified immediately and the machine is not to be used until repairs are completed.
To Stop the Scrub Cutter:
1: Move the throttle control to the STOP position.