Beekeeping/British National (or Modified National)
At the opening of the 20th century the dual-walled WBC hive was the most popular hive type used in the UK; however it was complicated to manipulate and by the 1920s alternative single walled designs had overtaken as the most popular hive types. One such single walled hive was chosen by the Ministry for Agriculture and named the 'British National'.
A standardised national hive design was seen as important enough for the British Standards Institute (BSI) to issue British Standard 1300 in 1946 which formalised the dimensions of the WBC as well as giving the design for the single walled 'Modified National'. Shortage of wood supplies following the war caused the popularity of the dual-walled WBC to fall even further.
BS1300 was revised in 1960. It was subsequently allowed to expire but the design laid out in BS1300:1960 is still the most popular hive design in use in the UK.
There are several difference between the British National and the Langstroth Hive:
First is the location of the bee space. British National frames hang level with the top of the box with a bee space gap at the bottom; unlike the Langstroth where the bee space is at the top of the box.
Secondly the rebates in the British national box used for hanging the frames are wider allowing for longer top bars. The British National has a top bar of 17" with a comb width of 14", giving a 1.5" lug on each side compared to 7/8" on a Langstroth frame.
The third main difference is the overall dimensions. The external dimensions of a British National box is 18 1/8" square.
Brood box 
The British National brood box is 18 1/8"x18 1/8"x8 7/8" made from 3/4" timber.
The internal dimensions are 16 5/8"x14 5/8" due to recessed side panels. This is then filled with 12 frames, or 11 and a dummy frame, each having a comb area of 14"x8 1/2".
Shallow box (Super) 
The British National shallow box is 18 1/8"x18 1/8"x5 7/8" made from 3/4" timber.
The internal dimensions are 16 5/8"x14 5/8" due to recessed side panels. This is then generally filled with 9 or 10 frames each having a comb area of 14"x5 1/2".
A shallow box may be used as an extension to the brood chamber (known as brood and a half). In this case the shallow box would be filled with 11 frames and a dummy frame or 12 frames.
Deep Brood Box 
Many strains of honey bee bred in the UK are not comfortable with their brood restricted to a single national brood box. It is quite common for brood and a half to be used and with prolific strains such as Carniolan even this can be too little and two full size brood boxes are used.
While it was not part of the original standard it has become quite common to use a deeper brood box allowing the use of 14"x12" frames. Comb area of various brood chambers are given for comparison below:
|Brood chamber type||Comb Area|
|Single National Brood box||2618 sq. in.|
|National 14x12 Brood box||3696 sq. in.|
|Brood and a half||4312 sq. in.|
|Double National Brood box||5236 sq. in.|
- Recessed sides of both brood box and supers provide a firm hand hold for lifting
- Smaller size of supers make them easier to lift
- Square profile of boxes means they can be rotated through 90 degrees on the floor allowing choice of having combs running parallel to the entrance (warm way) or perpendicular to the entrance (cold way)
- Reduced comb area in brood box can lead to congestion of the brood nest with prolific strains