Bob sled questions

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  • #81490
    wild millers
    Participant

    Here are a few questions for the experienced bob sledders in this forum…

    I recently picked up this sled for a few dollars from a neighbors barn, he basically just wanted to see it get used. It seems to be solid, been stored under cover for many years, all oak frame work is sound and the iron all has surface rust but nothing serious. The steel runners under the ski’s are about 1/2″ thick and look like they have never been used.

    First of all does it look to you like I have it set up correctly for running the sleds tandem? (I know the tongue is not attached at the moment, that does need a little bit of strengthening)

    Second, I understand the principle of bridle chains and their advantages but can’t figure out how the chains in the photo would be used as such, or if they are meant for another purpose? Also I notice the steel U bolts that are on the end of each bunk, underneath, and just inside the stake pockets.. any thought on what these would be for?

    Also the bunk on the front sled looks like it is meant to pivot, two heavy steel plates are the only contact point between the bunk and the sled below, with a 3/4″ hole that looks like its for a big pin to pivot on (there is no pin included, would that be a through bolt or loose pin?). If I were to use one of these sleds single for logging, do you find that a pivoting bunk or a solid bunk works better for moving through the woods? I imagine that a pivoting bunk may turn easier, but may also move around too much to be comfortable when loaded with logs and your trying to ride on top?

    I would like to mostly use this as a single sled for logging with the team but I would like to build a deck that could be placed on both sleds when they are set up tandem for moving hay and doing sled rides in the winter.

    Any thoughts or comments would be greatly appreciated. Thanks -Joel

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    #81494
    Does’ Leap
    Participant

    Hi Joel:

    Glad to hear you picked up a bobsled. I am a huge fan of my single sled for logging. I am going to let Carl answer those questions. In the meantime, here are some links to previous discussions:

    In Search of a Bobsled

    Chaining Loads on a Bobsled

    Single Swiveling Bobsled

    George

    #81503
    Carl Russell
    Moderator

    Joel, it is difficult to determine answers from photos sometimes. Also in this day and age of standardized fabrication it may not seem plausible, but it amazes me how designs differ so greatly even within regions.

    I am pretty sure that the “U”-bolts are to attach planks for the bed that would reach back over the rear bunk….. which would require the front bunk to swivel.

    I have found that a swing bunk can be problematic when loaded with logs as it can become unstable on turns. As the sled moves out from under the bunk, the weight of the load can tip the bunk similar to the old-style hay wagons with the axles that pivoted under a pin. This is especially true on sidling hills.

    I have solved that by putting extra bolts/pins down through my bunks that can be removed when/if I want the bunk to swivel. Generally the attachment for a swing bunk is a large pin, not a bolt. With weight on, it is unlikely to bounce up and out.

    As far as the chains, I am not certain that they are bridle chains. Any breaking chain I have ever seen has a mechanism that allows the chain to be undone when under extreme pressure. These would not work as such. In fact they actually look more like attachment chains that would be on the front of rear runners of sleds that had swing bunks fore and aft. Those chains would cross from the rear of one front runner to the front of the opposite rear sled runner so that sleds would track each other on turns.

    I think you could easily use the front sled alone to move logs. The runners on the rear sled are too long to maneuver easily under load. I think there may have been a different rear sled that was used with a plank body. Most double-bunks that I have seen with plank bodies either had no reach, or had the reach attached directly into the front swing-bunk. I worry that the way this is attached the angles would not match up, putting pressure on planks and/or attachments.

    I think this double set-up would probably work fine for logs, but it is interesting to me that the rear-sled bunk does not have stake pockets……

    It all looks heavily built though… can’t hurt to play around with it…. remember it is more of an art than a science. Also wouldn’t hurt to get some insight from a few old-timers in your neighborhood.

    It would be good to see a pic of the front-sled pole, roll, and attachments. You’ll want to make sure they are pretty rugged if you want to use it for bobbing logs.

    Carl

    #81504
    Livewater Farm
    Participant

    years ago I had a heavy log sled built by a blacksmith from Nova Scotia who came down to work in the Boston ship yards and later the logging camps of the Berkshires and southern vt hilltowns and had a shop in Whitingham Vt Percy Dodge

    the sled was similar in that it had chains on the outside of the front sled runners somewhat like yours and that is where you hooked your singletrees no evener

    The the idea was to pull the load from under the point of weight of the butt end s of the loaded logs and the runners walked some what
    used it for years and worked just fine not sure if yours is not some mast produced version with those cast bunk lifts

    just saying maybe
    Bill

    #81505
    wild millers
    Participant

    George, Thank you for the links, I learned a lot from reading those over, I’m sure they will be very helpful to revisit once I’m playing around with learning about chaining loads..

    Bill, interesting, I hadn’t thought of that. The chains do look like they are meant for pulling each ski individually but the ski’s are 45″ wide center to center. That seems like a wide span to me which would also call for a 45″ neck yoke? I really don’t know though having never used a bobsled, it does sound possible. Also no evener came with the sled. There is a hole in the tongue were it looks like an evener might have gone but its only 7′ back from the tongue cap which wouldn’t fit my team very well I don’t think.

    Carl, Thank you for your insights as well. The “U” bolts do seem like they may have attached a deck to the bunks..they are on both the front and back bunks.

    Your right the chains do not seem like any sort of breaking chain and in this picture it does look as though they are meant for pulling each ski. There is no chaining point on the rear of those skis for chains to cross from tip to the rear of the opposite ski as you were saying is sometimes done for a rear bunk that swivels (this one does not).

    Your absolutely right about talking with some locals about the design, I should have thought of that already.. I put a call over to Les last night and it sounds like we may have him over for lunch next week to talk bob sleds. I know we’re looking forward to that.

    Finally I have added a picture of the tongue and you will see how it is lacking in strength. There is no bracing on it where it tenons into the “roll?” and there is slop in that right now. I think some heavy bracing there would be called for. You can see two steel bars bracing the stub tongue on the rear sled..is that what your calling the “reach”?

    Also the ski’s on both the front and rear sleds are both 7′ long, and there are stake pockets on the front and rear bunks.

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    #81519
    Carl Russell
    Moderator

    I can get a better sense from those pics. I have never used a sled set up with individual hooks for each horse, but had thought that was what it looked like. Puts much less stress on the pole and roll that way, but need some pretty stout horses to work individually like that. I suppose you could find some way to use a spread-chain to center the hitch, then attach an evener.

    Funny how limiting photos can be. I can see a lot more of the sled now. I can see how the rear sled will track well enough to manage a plank body.

    If you are on typical SE NH land, I would be inclined to use the sled double even when hauling logs. Loading is not that much more difficult than with just the front bunk, but it will travel a lot easier over moderate terrain when loaded, and you just need one good chain and binder to hold the logs down.

    Les will have a good eye for the condition of the wood, and/or other fabrication improvements, as well as hitching insights. Don’t be hesitant to tap that resource……

    Good luck, Carl

    #81520
    Does’ Leap
    Participant

    One thing to consider if you are debating between one and two sleds for logging is the layout of your woods. If you have nice looping roads/skid trails, I bet those double sleds would work slick. If not, I think it would be very difficult – if not impossible – to back those sleds. I use a scoot with 12′ runners and one of its disadvantages over the bobsled is it is harder to back and maneuver in tight places. Let us know how it works out.

    George

    #81530
    Brad Johnson
    Participant

    Keep in mind, too, that a scoot gets the wood completely off the ground, which is advantageous when pulling long distances over flat or uphill ground. The bobsled works best when you are going downhill, particularly in the winter, but is more challenging on flats or uphill skids.
    -Brad

    #90020
    wild millers
    Participant

    Fast forward 4 years!

    We’re established on our own woodlot now, mostly flat ground, and I have laid out all of our skid roads in loops for ease of working horses.

    We used the double bob sled for the past two winters as a people mover for sleigh rides but this winter I removed the deck, and bolted two 3X4 oak rails between the bunks to set it up for logs.

    I’ve been forwarding about 1000′ from where I’m cutting this winter to the landing and enjoying it greatly. It’s moving quite heavy loads without excessive strain on our unshod horses.

    Here are a few pictures loaded with firewood. Some loads of bole wood and some of limb wood which I wouldn’t otherwise have taken the time to skid out.

    Thanks for your thoughts Brad, George, Bill and Carl. I have had them in the back of my mind for the past few years! -Joel

    • This reply was modified 7 years, 3 months ago by wild millers.
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    #90024
    wild millers
    Participant

    ..

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    #90028
    Carl Russell
    Moderator

    Looking good Joel… great job, Carl

    #90029
    Ron
    Participant

    Hi Joel
    Why do you need the three by four oak rails between the bunks? Not sure I understand the purpose?
    Ron

    #90030
    wild millers
    Participant

    Sure Ron, Let’s see if I can put this in the correct terms…Basically the oak rails between the two bunks turn them into a single rigid platform in this case for loading logs onto. Since the bunk on the rear bob is rigidly mounted to the beam and the front bob has a swing bunk (meaning the bunk pivots on a heavy pin dropped through the center of the beam) that lets the front bob pivot under the load for the whole sled to follow. Picture it like an old wagon and replace the sleds for wheels and you can see how the front “axle” must be able to pivot independently from the rest of the rigid wagon bed.

    Having a solid deck built on the sleds achieves the same purpose, as I have had it set up the past two winters. By removing the deck portion it brings the log platform down to the bunks themselves and therefor closer to the ground making it easier to load and removes unnecessary weight.

    Finally having the oak rails bolted on the underside of the bunks, it makes a very convenient ledger to rest poles on for rolling logs up onto the sled.

    If anyone has more insight to add to this please feel free. -Joel

    • This reply was modified 7 years, 3 months ago by wild millers.
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    #90033
    Carl Russell
    Moderator

    I guess the point is Joel, that other than as a ledger plate for rolling logs on, the logs should replace the need for those oak rails. On some sleds the reach from the rear sleds tenons into the swing-bunk anyway.

    That being said though, if the swing bunk and rear bunk are not attache they can move independently of each other which can cause problems for load security.

    It looks like a well-used piece on your farm. My hills are too steep, up and down, for a double bunk sled, but I have always coveted using one.

    Good job, Carl

    #90034
    Ron
    Participant

    Hi Joel
    Thanks for the clarification. I can see that the oak would be helpful for setting your skids on. I have never connected the two bunks just used it with out.
    Just as an aside it is always interesting the different terminology we use. In the Ottawa Valley the sleighs you call bob sleds are called sloop sleights and are use extensively in winter to haul logs hay or any heavy large loads but the term Bob sleight is usually refereed to as a light weight two runner sleight for carrying people or small loads. There is no set rules on naming but this is a great place to share and exchange terms and ideas. Thanks for your patients and sharing.
    Cheers
    Ron

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