been a bit since i've posted much up but i've got a couple more questions to see what others are thinking....
? #1: Do you use your aerial as an HD and/or Crane?
I'm looking into what other departments do for SOP's so we can develop ours where I work. We have various ladders in the city, straight sticks, buckets with 250-1000# tip load, from 75-110' in length.
I see that there is value in using them as both an HD and a crane. I looked into the laws regarding using them as a crane and have found no OSHA rule, CFR, state law, state administrative rule, manufacturer rule, or nfpa recommendation that would forbid this. The only thing definitive that i've been told is don't exceed the tip load by the manufacturer (pierce) and that the aerial doesn't know if the weight is on the top or hanging from the bottom of the ladder.
If you have thoughts, detailed rigging methods, physics discussions, i would like to discuss them so i can present ideas to my department.
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06-02-2010, 08:50 PM #1
Aerial Ladder as High Directional or Crane
06-02-2010, 11:46 PM #2
Mike, what do you mean by "crane"? This concerns me. If you are using the mechanics of the aerial device to lift a victim the problem comes from lack of control and the amazing force you can exert on the patient if he hangs up on something.
The use of an aerial as a high point is a great thing, we train with our truck companies about twice a year to assist TRT with high angle rescue. Few things to keep in mind setting up this system. Your MA system needs to be on solid ground. Having the people in the bucket controlling the system adds to the complication. Your progress capture needs to be on the ground too.
Use a tag line to vector the patient back to the ground once raised out of whatever you were hauling him out of, do not traverse the aerial to move the patient, this can lead to uncontrolled movement.
06-03-2010, 12:30 AM #3
I guess what i mean by crane is just exactly that. placing the aerial over the victim with some sort of bridle connected directly to the lifting bar/eye or rigging going down the axis of the ladder to a cd or anchor at the base and using primarily the system for raise/lower operation and the aerial in rotation.
I find that i'm more concerned when the aerial is used as a HD than as a crane as the forces you impart on the aerial can be much greater if you are not aware of what you are doing. a single load hanging off the bottom of the tip is no different force wise than someone on the rungs, where as using the tip as a cd invites force multipliers into the game. i'm not advocating not using the aerial as an hd just trying to understand where the concern lies around not using it as a crane. the setup time would be much more rapid as crane and physics wise is nothing different than moving the aerial with a person on the tip. i know people don't advocate doing that either but sometimes that is a necessary task. i've worked on a busy ladder company for the past 10 years and we don't move people regularly but there are times when that is the safest tactic for the given situation. our sop's state that we won't extend/retract the aerial with a person on the tip but no restriction on raise/lower or left/right. spotting the aerial in smoky or dark conditions this is the best/safest technique when it's difficult to judge distance or to see what you are shooting for.
controlling a load on the tip hanging from below would be relatively easy task especially if the length of the bridle is minimized and the pt is closest to the tip. tag lines might be necessary as well, if in a stokes, one at the head, one at the foot.
if the risk is there of hanging up on something then the crane method should be out in my opinion. i totally agree with you on that.
i think having several methods of using the aerial in rope rescue is beneficial and should be looked at from a critical eye. many departments do this (ft lauderdale, seattle, san diego) and i think that craning would solve many situations quicker than an HD. I originally saw a video of ft lauderdale removing an injured pt from a residential roof quickly with an aerial where they placed the tip over the pt, packaged him in a stokes, connected it to the tip, raised it, swung, lowered onto the gurney...
just my .02, really appreciate the feedback and look forward to more discussion.
06-03-2010, 11:55 AM #4
I like this discussion, be sure to read the last paragraph, as I am not discounting your method.
I see your concern with the force multiplier using the tip as a high point. If you set up a pulley on the tip and use a haul system, directly below it you double the force. A 200lbs load becomes +400lbs on the tip when you haul. You combat this with angles, easy way is to set off your haul system to the side. You can also bring the rope back onto the aerial a few rungs down, and run it down the ladder to the ground. This way you can manage your angle and force applied; using a 60 degree angle a 200lbs load will then exert +340lbs on the tip (about 170%). Best advice is to know your equipment, and what loads you can subject it to.
As for using as a crane; It can be done, but the problem comes because you don't keep your attachment point at the same vertical spot. Think about this, when you raise the ladder, it pivots on the axis at the turn table.
Take this scenario, it is a deep trench you are working on, 15 feet, trench walls are shored, all is safe. Worker fell into it and has suffered all kinds of broken trauma stuff. Team enters, packages pt in stokes, blah, blah, blah and you are going to hoist with an aerial using this "crane" method. Say the set back from turn table is 30', and you start with the aerial at a 30 degree angle. That means that your ladder is extended 34.5 feet and the tip is ~17' elevated above turn table, add in ~10' from turntable to ground and 15' from ground to load. Ladder tip to pt is 37'. To "crane" the patient up to ground level you must raise the tip to 46 degrees to clear 15', but to clear that without extending the ladder as you raise you will be off target by 10'. You CAN do this, but you have to extend the tip out to ~44' while doing so. You can't just raise the ladder. Most TRT folk will not trust the agility of the aerial operator to guide this function. (I used this triangle calculator to get the angles/distances)
Not saying this "crane" method does not have an application. That is the best thing about being a firefighter, we approach rescues with open minds, and are able to adapt to any situation. The crane method might work well for removing someone from the top of a building, tower or structure, but there are just so many easier methods.
06-03-2010, 10:20 PM #5
- Join Date
- Dec 2009
Our department in Canada actually does use our aerial as a lowering device. We ran into problems with taking patients off of the great lake freighters docked for maintenance in the winter. We were unsure if it was acceptable for that use so we checked with a ministry of labour representative and they said it was acceptable. The people who developed this idea within our department did their research and checked with the people enforcing the regulations. We attach our stokes basket with two points of attachment, one to our rescue attachment and one on the beam on our pierce 75' ladder. From there we use two tag lines attached to the basket to keep the movement limited with the pt inside and can control it from the ground. It is a very basic setup but it was approved by a ministry of labour official in our area. It was developed strictly for that use. May sound crazy to some people but it has worked well for our department.
06-04-2010, 12:12 AM #6
thanks for the comments. i totally agree with you and think that the trench scenario is a prime example when you wouldn't crane someone. balancing the extension, raise and swing to keep someone at a specific point in all axis' could be tricky. however, there are many situations where the hang-up concern isn't there and the crane would be good.
i think a hybrid of hd and crane is going to be most valuable so you avoid ext/ret and raise/lower. primarily used for swinging a rescuer in or a pt out of the hot zone. if you were to rig a raise/lower system through the tip (from a lift bar, load sharing anchor, etc) and use that for lifting the pt then once they were high enough to clear the obstruction you could slowly swing them out and for that matter once there is no hangup concern lower them with the aerial or rope system, whichever the location dictates. all the time the rope system operator needs to be aware of what changes in position of the aerial does to the rope system (ie if you were to extend/retract then you'd have to tend the descent control device or tend the prusiks) so you don't suck the pt into the tip.
do you have any pics/diagrams/sop on the use of your aerial as either an hd or crane? trying to put together a proposal that is well thought out and covers all the ideal options.
06-04-2010, 12:05 PM #7
Yeah, if you guys are adventurous enough there is not limit to what you can accomplish. I have been to many tech rescue classes, and a few times this discussion comes up in some form. Hanging a patient from the end of an aerial and using the mechanics of the aerial to move him up/down/in/out and especially traversing around is a general no-no. Our tower ladder companies have an attachment that cradles a stokes on the front of the platform, this is fine because the pt is attached hard to the aerial platform, not dangling below.
But if you come up with a system, and train on it great. Just telling you a lot TRT teams would put this option near the bottom on the list.
I don't have any SOP/SOG on it, but I am good with Google. Here is Tempe's Truck SOP; about half way through is a stokes section. The do mention moving the aerial. Hope it helps.
Last edited by FiremanLyman; 06-04-2010 at 12:07 PM.
06-04-2010, 01:13 PM #8
thanks again for the comments. tempe's manual shows exactly what i'm looking to do (pg 7 shows the combination of rigging on the aerial and talks about moving the aerial once the stokes is in position).
So i guess i wonder where the is opposition to this technique comes from? that is the root of my questioning. I know many depts (san diego, seattle, tempe, ft lauderdale) do it but yet it's frowned up, why?
here's a diagram of a recent scenario we had at annual multi-company operation.
The basic gist is that there was a collapsed building with a barrier to access the area from all sides. we had to make access over a wall that had a collapse potential making the aerial a requirement. we had several of these scenarios (w/o people involved) 2 winters ago when we had a record snow year followed by rain. buildings were collapsing daily with the outside wall left intact many times making access difficult.
to continue, there are confirmed pts in/on the rubble. there is not an easy way to rig the system so you can use an aerial as an hd here since you have a large setback making an offset a challenge.
tempe's manual shows this and here is also a picture of san diego's rigging for the main line only (belay hasn't been rigged yet).
basic steps would be:
1) set aerial at angle that would allow for entire operation, do a test run to make sure you clear everything with anticipated load under aerial tip
2) rig rescuer into system. raise rescuer up on rope system to clear wall, not using aerial.
3) swing aerial with rescuer attached, taglines to rescuer
4) lower rescuer with rope system to pt
5) reverse operation with pt on aerail, rescuer operating a tagline if needed.
6) lower pt to ground once outside of collapse zone.
7) repeat as necessary
06-04-2010, 02:08 PM #9
Well see, you already had it figured out. And like I said, if you have developed a technique and trained on it, feel comfortable doing it, go for it.
The scenario shown is one of the more complex ones I have scene. This is a unique approach and a prime example of showing what some creativity will produce. Having done structural collapse training (50+ hours of shoring, breaching, lifting, searching, etc...) I would beleive that the patients would not be easily accessible, requiring to raker shore walls, lift structural members, probably breach a lot. But you said you have had several of these scenarios 2 years ago? Were pt's trapped in these structures? Please tell me more (always willing to learn).
The opposition comes from the possibility of uncontrolled movement. Using tag lines and raising the patient up as close to the tip before moving the aerial will mitigate him swinging around. The complexity of pulling in slack while retracting the ladder will take a lot of coordination. That is great if you have worked out this coordination. But this system is complex, and in our TRT we try to limit the number of devices and systems to the lowest level. This reduces the number of things that can go wrong.
06-04-2010, 02:29 PM #10
I do like the system that is set up on your aerial. We only have the anchor attachment, not the pully system on the tip. Is that a double pully? you could put a 4:1, even a 5:1 on this setup. That set up solves a lot of things, nice huh? Your ladder angle then also plays a lot on the tip's loading.
06-04-2010, 06:42 PM #11
- Join Date
- Feb 2009
we set up the stick up for a lift with the stokes basket. We do not use a pulley or anchor at the top. we run the rope down to the bottom of the ladder and then anchor off onto three points. We have biners to lock to the bottom anchors however in a pinch i have seen it done with a pompier belt clips. by using extend/retract lift/lower and left/right you can move the stokes basket. and of course you need a tag line onto the stokes basket. One thing that we do differently is we dont run the rope over the top. We use the 2nd rung down from the bolt on tip. This way you are not relying on the four bolts that hold the tip on.
Our department does not ban it from use. however the tech rescue guy get their panties in wad because the say it is a tech rescue job.
06-04-2010, 07:14 PM #12
06-05-2010, 05:36 PM #13
07-14-2010, 11:37 AM #14
- Join Date
- Feb 2006
Looks like everyone has already provided some good info on your topic. Lyman has a good point that did not get addressed further. The issue of the belay not running through your high directional. You are introducing a possible dynamic event into a system that can not handle that kind of force. Traditionally, a belay should not run through a high directional this is especially true of aluminum truss FD trucks. In your picture, having the belay on the ground and running over the wall would not be effective. I can see how it seems logical to run it up top. If you need a 2 point system maybe a mirrored raising system or a static two line set up anchored at the tip. both of these systems will remove the possibility of a dynamic event and still give you two points. Like you said, people are using these ladders for all kinds of rescues. Just be careful and make sure you have good coms with all players. To address rules and regs: Your ladder manufacturer will have some good info using the ladder as a crane/HD. I see that you have the tip spreader bar so I'm assuming you have an aluminum ladder. I'm only addressing your pictures. In most rescues involving the ladder as a HD there is usually an opportunity to place a top belay on a structure.
Good stuff - thanks for the topic.
07-14-2010, 12:34 PM #15
- Join Date
- Jan 2000
- Somewhere in the Backcountry...
I've enjoyed this thread from the sidelines. Very interesting and a good discussion.
So from left field....
Depending on how high you need to get to clear the wall and availability of anchors (i.e., BFT), what about a high-line?
Think of all the fun TRT folks could have with that one!
07-15-2010, 11:03 PM #16
07-15-2010, 11:34 PM #17I am now a past chief and the views, opinions, and comments are mine and mine alone. I do not speak for any department or in any official capacity. Although, they would be smart to listen to me.
"The last thing I want to do is hurt you. But it's still on the list."
"When tempted to fight fire with fire, remember that the Fire Department usually uses water."
07-16-2010, 05:39 PM #18
- Join Date
- Jan 2000
- Somewhere in the Backcountry...
09-29-2010, 02:49 PM #19
- Join Date
- Apr 2001
The biggest hurdle with alternative use of your aerial is training. Everyone must have a thorough understanding of the forces at play and the limits of your aerial. My department has a pretty extensive training on using the aerial as a "crane" and a high-directional. The training materials are readily available and each ladder company (15 of them) train regularly on the department's chosen methods. There are so many factor's that affect the capacity of a ladder such as material, how much ladder is out, angle...Personnel MUST have knowledge of how these affect the rescue, much like they must know how each affects the the ladders capacity during tradtional use.
The main concern with a ladder is pulling the load out of line to the stick and creating torque. This is why many feel using the ladder as a high directional with the ropes running down the bed of the ladder is a better option. The rope can still be used under the stick, but it must remain in line.
As far as using the ladder as a crane...Trust me the aerial vendors know what we are doing with their products. Our company was contacted by Pierce to work with their engineering department a few years ago to help them understand and in turn design a better system for aerial based rope applications. We did some preliminary work, but eventually interst died down and the project was put on the back burner. We'll see what the future holds.
Stickboy - The method employed by your department certainly is adequate. Again, I would explore the limitations of the rigging. For instance, you create a 2:1 on the tip from the get go, thus reducing the ability of the ladder to support more people or more weight. As long as the guys and gals know these limitations no harm - no foul. I think you all have a very creative way to rig your ladder.
We use Smeal and our pulley design is actually set back onto the steel part of the ladder. Your model ladder and the pulley design may limit the capacity of the ladder in "rope rescue" mode as everything is attached to the egress tip. This tip generally carries a lower weight capacity than the body of the ladder. (Some plates actually say "Egress" and have a load rating.) I have seen older ladders that have a 1,000 lb tip load, but only a 500 lb egress tip load.
Figuring the tip load is rather easy. We know that the rope as it hangs from the tip will form a 90 degree angle to the ground (the truck) and the inclinometer will give you the ladder angle at the base. The angles of a right triangle should add up to be 180 degrees. Therefore, start at 180 subtract 90 and subtract what the inclinometer says. The result will be the angle the rope and the ladder make (the COD angle). From there you can apply what you already know about COD multipliers. This may not precise, but it will give you a good way to estimate the effects of the load on the ladder. Obviously, strategically placed load cells and known loads would be the best way to see what your system is doing.
09-30-2010, 09:29 PM #20
My company does quite a bit of this type of operations, for the most part the aerials and tower ladders are used as high points primarily for below grade incidents. The aerial devices are used only for high points not for movement of patients, this was a pretty hot topic a few years back when an aerial was used to swing the patient and rescuer around to the street.
We rig the high point off the aerial or preferrably the bottom of a tower ladder bucket and this high point gets the main line. When safe and practical the safety goes over the edge, if not it goes to the high point. The retrieval is done either with a piggy backed 4:1 or a z rig off of the lowering device (we use an MPD). Hauling off the main line rather than a direct 4:1 into the high point has many advantages and works in our urban setting. We rig the high point and then position it over the objective and the operating pedestal manned or apparatus shut down to avoid any "accidents." Also regardless of how you do it, use tag lines to help manuever the patient on the way up or down.
As for the high lines... time, equipment, training and manpower are lacking in just about any incident where we are hauling a patient. Typically we are going up or down not spanning wide open areas.
Last edited by jfTL41; 10-29-2010 at 09:32 PM.
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