Hi all,
first time posting,
a little bit about my self first.
20 years of working dogs in Protection and Search areas.
I currently manage 50+ dogs for a security company ranging from Springer, Cocker Spaniels, Labradors, Large Munsterlanders and German & Belgian Shepherds.
I am dipping my toe into the dark and mysterious world of creating our own line of Labradors for use exclusively in house. As I have no experience within the Gundog/ Shooting world I am struggling to determine the best lines to chase. I would really appreciate any advice you can all give or pointers towards some of the best working bloodlines available.

What use in the house? 

I've done a bit of working trials training with one of my Labradors, sadly no longer with me, and, as much as she loved taking the sleeve and tracking criminals, she was a big softie at heart.  All my dogs will bark to alert me there's something going on, but are more likely to lick an intruder to death.

Hi Jason, it depends on a few things such as the job you need it for and your training style . For example, Drakeshead lines are generally quite small, lightweight and agile, so may be better suited to some types of work than heavier set lines, but they can be a little 'keen'. It would also depend on your training methods as well. Drakeshead lines can be quite sensitive so may not tolerate heavy handling which some lines would.

All our Labradors are used for Explosive Detection, Narcotics Detection or as Botannical Detection Dogs (Knotweed).
we tend to use German Shepherds or Belgian Shepherds for Guarding Duties.

thanks for the reply.
we are after very highly driven Labs. a smallish body is a plus as our handlers will need to pick them up and climb up into cabs of lorries (depending on use) etc so a larger lab can cause problems along the way. We like the "keen" ones
I will not tolerate any heavy handed tactics from any of my staff. All teams are actively encouraged to even think of "voice inflection" when operating our teams. my primary concern has always been the dogs welfare over the handlers. I can get a bit grumpy when i see someone misshandle a dog

This is important to me too. My weight limit is around 25kg so that I can lift over a barbed wire fence if necessary. My dogs tend to sit around 24-25kg, the bitches between 22 and 24kg. These are Drakeshead lines.

I would look at some of the lines used for working trials in the gundog world to see what crops up, Google will give you that.
Have you contacted any of the Police units, Metpol especially about the lines they have used with success regarding Labs? Not every force has it's own breeding unit.

I know a good few lines of working Labs but don't know how they would fair in scent detection but I would assume quite well. They do perform well in the working trial field for gundog work.

I think it's how long is a piece of string, I have show/dual purpose Labradors, I only keep bitches as it's easier to stick to just having one sex, two of my current girls are pretty compact, but are pretty much within the range for a Labrador retriever.  I think sometimes people think Labradors should be bigger dogs, but they are a medium sized dog, I've seen some larger springers that are nearly the same size as my girls. 

One of my pups (and I'll just add the proviso here that I have no litters planned at all for the forseeable future) now in Germany has just passed her conformation test, the only fault with her was that she is 1cm under the ideal height for a bitch, at 53cms high at the shoulders.  Her mum, who I have is usually around the 25-26kgs, although we're still trimming up some loose skin after her last (and final) litter.  I've seen working bred dogs that are larger, just not as substantial bone. 

I'm happy to pm details of the pedigrees of my girls if wanted at all for info looking into different lines.

I know some of the breeders that have supplied various forces.(i used one last year to sire one of my litters) last year we did 26,000hrs of contractual hours with our Search Dogs. I know there have been varying amounts of success with in house breeding by various Police Forces.
I am really looking at working lines only to source two Pups from and i would need them soon'ish.
It definitely is a minefield trying to find the right pups especially when the failure rate for training a search dog can be 50%!!! so in order to attain the best possible chance of success I'm after the strongest line i can get. I have Drakeshead,Glenbriar, Endacott, Riversway & Craighorn plus a few more bloodlines in my kennels. But i don't really know that much about whether these lines are the best or where i should go from here. any advice is more than welcome.

It really depends what you are after as an end result, I work my dogs, my youngest has Charway, Linnburnhead, Brigburn and Balrion Weathertop in her pedigree (not all of those are still working their dogs now), and when you go further back more working lines.  She will definitely work, but she's not the easiest character, very intelligent and busy, but then I prefer a pup/dog with a bit more character rather than one that just waits for you to tell them what to do. 

Drakeshead is an odd one, they buy in a lot of dogs, so their kennels is a mixture of their own breeding, and dogs from others.  Do you mean Greenbriar?  I'm not hugely up on the working side, but do recognise the names in pedigrees when looking through generally.  Have a look through the IGL retriever championship information, there will be well known FT dogs in there, but FT doesn't necessarily equal that the dogs have been worked. 

You won't get many pups soonish, unless you just plump for pups that become available, rather than exactly what you want.

My father has a male sired by a Riversway dog. He is working lines but never worked.
You also have Wylanbriar and Highholt lines too

I would speak to the SWDI: https://www.facebook.com/swdiab/

They are the top of the field when it comes to training up working dogs for detection, and they often post videos of incredible working Labs on the job that sound just like what you're looking for - have a look on their FB page to see. If you could buy an hour of their time to talk lines and things it would be well worth it IMO.

You could look at Highhouse Labs, their dogs are used for search and rescue and they seem to have a well thought out breeding ethos.

Thanks for all the advice. it looks like i have some homework to do!