Mike Heritage FFF MCI UK

Fly casting and talking fly casting bollox

The Double Haul (amended)

The Double Haul does not load the rod deeper. There, you have it black and white. The only time the haul adds very slightly to rod load is just at the point where you are overcoming the inertia of the line in the rod rings, it’s a friction thing. Once line inertia is overcome the haul adds linespeed, that’s it’s primary purpose.

Amendment, I thought to rewrite the whole post but as it’s purpose was not to teach the double haul but to suggest you learn it, I won’t.

If you read Aitors comments and my replies (below) you will see that my understanding of inertia was wrong. Inertia is always present when accelerating an object (the rod and the line in this case) and there is a consequent additional load applied to the rod while overcoming this inertia, not just at the start of the haul as I stated. My statement that a hauled cast will have less bend (load) for a given distance than an unhauled cast to the same distance is still (I believe) correct. Neither does it detract from the benefits of learning the double haul so get out there and learn it. If you ever work out how it works let me know. 

 For a given distance cast the rod load is actually reduced from what it would have been if you hadn’t hauled.

 Eh!!. Ok, you want to place a fly at 50′, to do so without a haul you need to apply x amount of power to the rod. If you now decide to do the same cast with the same rod load but add a haul, and, let’s say for arguments sake that the haul added 10% extra linespeed which we will call y, you now have a linespeed of  x + y  and you have just plonked your fly at 55′ and lined the trout. To make the 50′ cast with the haul included you have to actually reduce the load on the rod. In other words you are spreading the work load from one hand to two. 

 You might even notice that when you start to double haul you start to rock your body backwards and forwards, especially as the casts get longer, and you are spreading the work load even more. It makes for a lot less tiring day, which your casting arm will thank you for in the pub later.

 I’m not going to try and teach you to double haul here but I urge any of you that can’t DH to take some time and learn it. I know it’s bit like rubbing your tummy and patting your head but with a bit of effort it becomes second nature and is well worth the effort.

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March 9, 2009 - Posted by | fly casting, Flycasting instruction, Mike Heritage

15 Comments »

  1. Hi Mike,

    “Once line inertia is overcome the haul adds linespeed…”

    If you are accelerating with your hauling hand you never overcome inertia, as inertia is the tendency that a body has to remain as it is; it doesn’t ever want to change speed or direction of motion.

    Cheers,

    Aitor

    Comment by Aitor | March 9, 2009 | Reply

  2. Hi Aitor,

    Another definition is; Resistance or disinclinaton to motion, action or change.

    In the context of my post the slight increase in rod load at the start of the haul is caused by the friction created by the inertia of the line.

    How would you define it?

    Mike

    Comment by Mike Heritage | March 10, 2009 | Reply

  3. As long as you accelerate your haul inertia on the part of the line will show up, cause the line resists acceleration. So that load due to the haul isn’t restricted to the start of that haul.

    If you want to cast to 50’you need a certain final speed applied to the line. For getting that final speed you need certain acceleration. Using only the rod hand you get all that acceleration from this hand, and this acceleration loads the rod due to inertia. But you must take into account that not only the line has inertia, the rod has inertia too. That’s the reason for the load you can get in the rod when you move it back and forth without any line threaded through the guides.

    If you go to 50′ using both hands part of the acceleration comes from the haul so you need less acceleration from the rod hand. The line hand only accelerates the line, but the rod hand accelerates the line (with its own inertia) and the rod (with its own inertia too). The haul loads the rod to some extent, but as you accelerate less with the rod hand the rod gets less load due to the lesser inertia on the part of the rod itself.

    Comment by Aitor | March 10, 2009 | Reply

  4. So is inertia the wrong word for the friction that has to be overcome at the start of the haul?

    Comment by Mike Heritage | March 10, 2009 | Reply

  5. It is not the friction what loads the rod, as the friction is a force that goes paralel to the blank. It is the inertia of the rod and that of the line what loads the rod.

    The haul accelerates the line so the haul loads the rod. However as when hauling we accelerate the rod butt less the load due to the inertia of the rod itself is less too, so it gets less loaded when hauling (though the hauling is loading the rod).
    Just attach the line to a fixed object and then haul the line while maintaining the rod butt static, then tell me what happens :^)

    Comment by Aitor | March 10, 2009 | Reply

  6. But we don’t load against a static rod Aitoir. I am totally convinced that apart from an initial minor extra loading on the rod when we start to haul the haul adds no more load to the rod, only linespeed.

    Comment by Mike Heritage | March 10, 2009 | Reply

  7. When hauling to get to the same distance, the acceleration of the line is the same, in this case imparted by both hands; but the acceleration of the rod itsel is less than when using one hand only, because we don’t need so much accelaration of the rod now (as we have the acceleration from the haul). As the acceleration of the rod itself puts a bend in the rod, less acceleration puts less bend.

    If the haul accelerates it adds its share of load. The question is that as, due to the use of the haul, we are accelerating the rod butt much less the part of the load due to the inertia of the rod itself decreases. So the whole load is less, although the haul adds load :^)

    Comment by Aitor | March 10, 2009 | Reply

  8. Just a little experience:

    Cast only with the rod hand and a fixed length of line. Then add a badly timed short and fast haul at the middle of the forward stroke. What happens?

    Comment by Aitor | March 10, 2009 | Reply

  9. If you finish the haul too early the rod tip will rise and you will tail. Wherever we put the haul it must end at or very close to RSP, preferably slightly after rather than just before.

    If I have reduced the equivelent load on the rod that I have added to linespeed with the haul how can the haul have added to rod load?

    Perhaps we should start a discussion on ‘loops, it needs a return to sanity after the recent drag thread.

    Comment by Mike Heritage | March 11, 2009 | Reply

  10. “If you finish the haul too early the rod tip will rise and you will tail. Wherever we put the haul it must end at or very close to RSP, preferably slightly after rather than just before.”

    Exactly. So if when we finish the haul too early the rod gets unloaded that is a sure sign of the haul loading the rod, cause if the haul doesn’t add load finish it eraly couldn’t detract any load from the rod.

    I fear this kind of debate on the Board :^)

    Comment by Aitor | March 11, 2009 | Reply

  11. We have haven’t reduced (well we have, but) rod load we have stopped accelerating the line with the haul, this sudden change of line acceleration is what causes the tip to rise.

    Mike

    Comment by Mike Heritage | March 12, 2009 | Reply

  12. Acceleration is what makes inertia to show off. If you accelerate the line with the haul it doesn’t want to be accelerated so it pulls the rod tip backwards loading the rod. When the haul ceases the rod tip rises, that is, the rod unloads. Pretty clear.

    I will send an email with a file trying to explain this more throughly.

    Aitor

    Comment by Aitor | March 12, 2009 | Reply

  13. You must take into account that the rod itself has inertia. If you accelerate the rod without line it gets some load. The more you accelerate it the more it gets loaded even without line.

    Comment by Aitor | March 12, 2009 | Reply

  14. “To make the 50′ cast with the haul included you have to actually reduce the load on the rod. In other words you are spreading the work load from one hand to two.”

    Mike, I am not trying to be argumentative with this, but we are not looking for a reduction of rod load. To make a cast to the same distance when using both hands we reduce the acceleration of the rod hand, and the reduction of rod load is a consequence of the reduction of rod acceleration.

    Cheers,

    Aitor

    Comment by Aitor | March 15, 2009 | Reply

  15. I don’t think I specified how the load was reduced. I merely pointed out that the work is now spread beween two hands and as a consequence the rod hands work is reduced comensurate to the amount of work the hauling hand provides. We have to be looking at a reduction in rod load compared to trying to cast a fly to the same distance without hauling. The casting angle required for a hauled and unhauled cast would be different, the hauled cast would have a narrower casting angle therefore there has to be less load on it.

    I don’t mind the arguement/debate, I have been trying to work out exactly how the haul works for years!

    Comment by Mike Heritage | March 15, 2009 | Reply


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