Top bar size?

[Jim7310]

Hi everyone,

I am new to the forum.  I have been keeping bees in Warre hives and am going to add a horizont top bar hive this year.  I have been reading, visiting forums and talking to local hTBH beekeepers and it has become obvious that there is nothing like a standard for hTBH size - most specifically for the top bar size.  Les Crowder, Philip Chandler and Wyatt Mangum (the three I have read the most about) all promote different top bar sizes ranging from 17" to 19". 

I am thinking that I want bars and comb from all of my hTBHs to be the same, so I have been agonizing (probably more than necessary) about picking the right dimensions for this first hive. I would very much like to hear from folks here what size top bars (length) and other hive dimensions you are using and why you chose those dimensions.

Thanks,
Jim
Central Indiana

[Michael Bush]

Well, I think you should go no less than 48" long and no more than 60" long.  It's hard to get them to use more than 60" and they tend to swarm with less than 48".  The bars should be no more than 19" long and no less than 15" long.  More than 19" and it's difficult to keep them from curving the ends off of the bar.  Less than 15" just isn't long enough...  The depth should be a one by twelve.  No point wasting material making it any shorter or deeper.

[Jim7310]

Thanks for the advice Michael. What length bars do you use and why that particular length?
Jim

[krista45036]

i bought 2 used TBH ( nice old comb in them!)  with 16.5" bars, all 1-3/8"wide, so i wanted to build or buy something similar to this.
found a KY fellow making TBH bait hives with 16" bars but willing to cut them 16.5".  i bought 3 and am very pleased with the interchangeability.  they hold 10 1-3/8" bars.   i'll use them for splits next year if all goes well; setting them out as bait hives this season.

there is no standard but being compliant with my starting hives is a step in the right direction for me.  strive for standardization in yr yard.

- krista

[little john]

I would advise to choose a top bar length equal to that of the most commonly used frame in your area. I guess that would be the Langstroth for yourself ?

When building a KTBH a few years back, I choose 17" (as per PhiI Chandler's design) as that is the length of the standard British 'National' frame's top bar - and for no other reason. It proved very useful to have some interchangability between Top Bar and framed hives - in fact, this feature became so important to me that I eventually butchered the 48" KTBH and converted it into a 2 x 24" Deep Long Hive to take 14"x12" frames. I'm hoping that this configuration will prove satisfactory - if not, then I'll simply remove the central divider, and run it as a single hive again.

LJ

[Michael Bush]

>Thanks for the advice Michael. What length bars do you use and why that particular length?

I guess I arrived at 15" for a couple of reasons.  I was trying to get a comb that could be cut up for cut comb and come out fairly even (five per comb, three across the top and two on the bottom) and I was experimenting on what was causing comb collapse and what would help.  The theory on what might help was less depth, sloped sides and less width.  The 15" ones were easy to handle.  The advantage to 19" is that it's the length of a Langstroth top bar.  The disadvantage to longer are the curved combs on the ends as the combs get longer.  The 15" bars with sloped sides, a one by twelve deep worked well.  The 19" with straight sides with 10 3/8" depth (a long Langstroth deep hive with just top bars) collapsed.  The 19" with straight sides and 7 1/4" depth worked well.  Hard to say how much was just luck or design since I only did one of each at the time of the experiment.  The long Langstroth deep size one may have been just a strong quick flow in very hot weather and so the comb was all new and heavy.  But it went down like a row of dominoes...

[Jim7310]

Thanks for the insights everyone. I am going to try working from Wyatt Mangum's dimensions using a 19" top bar. I like the rationale of using the Langstroth standard for top bar length but heeding  Michael's experience, keeping the depth on the shallower side.

Jim