@Andrew: And in conclusion, I have had "professionals" try to insult me or hurt my feeling (yes it is singular) and failed, what chance did your last rant had??.

John I don't think you have ever clarified anything in your life, because you have been too busy talking and giving your opinion. I gave the answer to what a working aisle was in my submission in about one sentence. I did it because the first two responders started talking about Right Angle Stacking Aisle which is not what the questioner wanted.
You then chose to pontificate and confuse the **** out of the situation with a paragraph full of the most B.S. I have seen in a long time.
The one that had me rolling on the floor was machining tolerances in the racks! What do you think this is NASA? By the time you add in all the variables of the pallets, where they are placed onto the racks, the rubbish in the aisles none of your stuff makes any difference.
But it does fill the air around your orifice.
Read what the questioner is asking, see if anybody has answered it and if they haven't try and answer it in as easy and succint fashion as possible. Without being a know it all. That's all you have to do without all this negative attention seeking.

@andrew: Please reread & TRY to understand what was provided in my post. my first point was SIMPLY to clarify what a "working aisle " is and what it is not. Didn't see a clarification in your post. Some people may not know how to determine it, especially the less experienced folks.
Secondly, why it is a REALLY good idea to add an extra 4" to 8" to the calculated right angle stack capability of the machine to avoid a very costly situation down the road (i.e. having to move racks). I SIMPLY was stating some of those contributing factors which can affect actual "real world"right angle stack performance capability - which ONLY ONE was tires. This can be likened to the advertised mpg of a vehicle vs what you actually get. Oh by the way most reach unit the drive tires can have , either a rubber type compound , some even impregnated with walnut shells (freezers) or polyurethane - these tires have all a different durometer ratings and will perform differently due to the difference in rolling resistance. Your tire supplier can provide that data the durometer ratings they are just a cell phone call away.
Note: It is always better to be over informed than under informed. Being under informed is similar to doing battle with a six shot revolver loaded with only one bullet.
If this info was too much for you to digest you had four choices 1. Don't read it 2. Ask questions to try to get a better understanding and be better informed to help your customers 3. Ask the FAC ADMIN to remove my post 4. Or provide a less than professional response - which is the option you chose.
Your 2 x 4 maybe be a good suggestion but it ASSUMES that the customer has a narrow aisle truck and racks have not been set. How would one determine aisle size when planning a rack system work aisle based on
pantograph reach (most common in the USA & Canada & very little in Mexico and almost non-existent in Europe - the ylike mast reach units) layout for a new installation or conversion from a typical counterbalance work aisle of 12' aisle (in the US) and possibly larger in other parts of the world as they use very little press-on solid tire units - primarily use pneumatic tire (tyre) units. The originator of this thread is not from the States and is looking for info on a Crown pantograph unit that is not very common in the UK and demo or rental units might be hard to provide and I AM ASSUMING they are doing paper study at this point and he just wants specs on machine capability to see how many more pallet slots they can add. I believe to answer his questions one would need to contact Crown but more information would be required by Crown, items such as - pallet sizes & design (GMA styles pallets aren't common in ), the EURO pallets are much different than in the US, load centers are based on 500 mm (~20") vs 610 mm ("24" in the US, will the bottom row of pallets be set on the ground or positioned on beams above the floor, mast lift height, attachment - like side shift, etc, etc which Crown & Raymond typically require before providing any work aisle requirements.

What's your point ? Do you think people are going to go out with a durometer and test tires? I think you are overly complicating things to show off your knowledge.
As I said earlier set up some 2" x 4"'s with your drivers and see how that works until you get comfortable with it.Don't make a mountain out of a molehill.

Seems to me that the working aisle is - the clear aisle distance (meaning either the distance between rack facings or pallet rack guards) or if pallets over hang the rack beam face, which is very common) the distance between pallets +the right angle stack capability of the machine w/pallet + add an extra 4" to 8" for improved productivity (meaning the operator does not have to be so precise when picking or placing a load) and other factors stated in the following. Actual machine right angle stack capability can vary from published specifications due to different floor surface concrete finishes (some floor finishes have a higher coefficient of friction than others), tire type (tire compound durometer ratings) , conditions of tires & environment (freezer, cold storage, wet floor surfaces, manufacturing tolerance (all metal machining, cutting, etc have a tolerance of + or - something as well as tire OD can vary slightly from one brand to the next - if a machine was build with everything on the + side of these tolerances (or as the design engineers say tolerance build up) it would not perform exactly as published or the engineers planned. etc). So the safe side is to add a few extra inches to allow for these factors. More than once has a customer set up his new rack system and found the truck he bought, couldn't work in his aisles- "and then the fight was on."

I think he said Working Aisle which to me means not the Right angle aisle.But the minimum aisle that I can use with my configuration of truck and my load (pallet whatever) to enter an aisle and turn 90 degrees to put the load away and exit.
The big factor here after we have sorted through all the technical specs and it gives you a number that is made for an Olympian Fork Lift Driver who has trained for six months for the test,is to look at your own operators. Basingstoke is not too bad but here we give them long service medals for showing up for three weeks. So you have to start adding on to that aisle dimension for the experience you may have in your drivers, or the consistent level you may reasonably be able to train them to with your labour force.
Then make a judgment based on the speed of your operation. Grocery warehouse being the worst where all has to be out by 4 a.m. and a regular finished goods warehouse with a steady flow of orders being the best.
Lastly where are you geographically with regards to labour and rack damage. Last time I was in Mexico I saw one forklift going down the aisle preceded by two helpers, you in the UK probably have the worst situation and want as little rack damage as possible within reasonable limits.
Silly as it seems I have had customers put 2" x 4" long lengths of wood or similar steel down on the floor and practiced with their drivers. A very illuminating exercise.

Danny,

The reason there is no easy answer on this is because it is dependent on so many factors; battery box size, ID/OD, outrigger dimensions, etc. If you were able to supply a serial number, I could give you a better figure. However, a solid number to go with as a starting point would be 102". This is based off of a typical GMA pallet, common battery box, and 3500# capacity single reach truck.

Hope this helps,

A

apparently crown thinks this is a trade secret?
there is no public information available on the aisle spec's for any of thier trucks... DOH!

but if you measure the total length of the truck with forks tucked in and add 2ft your truck should operate sufficently in that width of asile.
Most reach trucks will turn within the inside front load wheel and almost turn on a dime inside the inside loadwheel given on which way your turning.

I'm assuming in the neighborhood of 8ft to 10ft asile width range.