Figures for D-13 model
|Class Name :
||Klingon Bird of Prey
|Unit Run :
|Buruk plus 4,178 others built in total. 1,452 have been lost in all. 1,782 have been retired from service.
- ActiveCh'Tang 
- ActiveEtam - Missing Hegh'ta 
- ActiveKi'Tang 
- ActiveKorinar 
- ActiveM'Char 
- ActiveMa'Para - Destroyed Ning'Tau - Missing Orantho 
- ActiveQevin 
- ActiveRotarran 
- ActiveVorn 
2277 - present
||Length : 109 m 
Beam : 92 m
Height : 20 m
Decks : 4
30,000 metric tons
2  x Mark 6 pulse disruptor cannon , total output 10,000 TeraWatts
1  x with 35 rounds
|Defence Systems :
||Standard shield system, total capacity 324,000 TeraJoules
Standard Duranium / Tritanium Single hull plus 5 cm High density armour.
Standard level Structural Integrity Field
(TNG scale) :
|Normal Cruise : 5
Maximum Cruise : 7
Maximum Rated : 8.2 for 12 hours.
|Strength Indices :
(Galaxy class = 1,000)
|Beam Firepower : 200
Torpedo Firepower : 50
Weapon Range and Accuracy : 220
Shield Strength : 120
Hull Armour : 550
Speed : 581
Combat Manoeuvrability : 11,650
|Overall Strength Index :
|Diplomatic Capability :
|Expected Hull Life :
|Refit Cycle :
||Minor : 5 year
Standard : 5 years
Major : 30 years
Perhaps the most successful design of vessel in history, the Bird of Prey has been in service in larger numbers over more subtypes for a longer time than any other class in known space. First fielded as the D11 class in the late 2270s, the ship was built from the start to fill a variety of roles. As a special operations ship she could use her cloak to penetrate Federation border defences and attack lightly defended targets such as sensor outposts, communications relays and cargo craft, creating confusion in advance of a Klingon fleet attack. She was also a natural scout ship, ideal for locating and tracking Federation fleets from under cloak. During the long period of tensions between the Federation and Klingon Empire, many D11s operated as raiders, cruising deep inside Federation space to pick off occasional lone vessels or outposts.
The Bird of Prey was a potent threat to the Federation in this role, but many of its secrets were revealed when one was captured by Admiral Kirk in 2285. The Admiral was at this time operating outside of Starfleet authority,  and the vessel concerned later sank in San Francisco Bay during an attempted landing; 
nevertheless, on his return to Starfleet Admiral Kirk and his crew provided full details of the vessel's operation. The ship itself was raised from the water and subjected to detailed analysis. This provided crucial help in devising countermeasures for use against the Bird of Prey, allowing Starfleet to modify the sensor networks already in operation on its ships and installations in order to significantly increase their effectiveness. Despite this coup, these vessels have remained a factor to be reckoned with ever since.
The D11A was the next major variant seen by the Federation, a prototype developed by a team working under General Chang in the early 2290s. The vessel was capable of firing torpedoes whilst still under cloak, making it a potent threat on the battlefield. Unfortunately for the Klingons, this development was rendered almost useless by the use of plasma homing torpedoes which homed on the ship's wake.  A variant which appeared in the 2350s was the D12, which featured a cloaking device equipped with plasma coils. Unfortunately these proved to be defective, rendering the ships cloak highly vulnerable to ionic pulses. This problem was considered so serious that the Klingons retired the entire class from service. 
The D12s were replaced with the D13, a class which continues in service to this day, naturally having been vastly upgraded and refitted over the years. In design the Bird of Prey conforms to Klingon norms, with a single torpedo tube at the extreme forward point of the hull. The command centre is above this, 
with crew quarters - such as they are - located in the 'neck' section directly aft. The rear of the ship comprises the engineering compartments and a small cargo bay.  A pair of wings carry small disruptor cannon at their tips,  while an emergency torpedo tube provides a backup to the main armament.  The wings allow the B'Rel to operate in an atmosphere and landing gear is fitted, 
the first Warp capable craft known to have this ability.
The similarity between the overall layout of Klingon ships is is pretty close - a forward section with the bridge and some weapons, including a torpedo launcher, a connecting neck leading to an engineering hull, which has wing like structures attached to the body. The Bird of Prey does depart from the norm somewhat - the D7, Vor'cha and Negh'var all have nacelles at the end of the wings, while the Bird of Prey has disruptor cannon there, with the warp engines inside the engineering hull itself. The most obvious explanation is that the Bird of Prey is designed for atmospheric flight. The wings are occasionally seen to move up and down for this - to vary their geometry, not to flap! One could say that the Klingons couldn't work out a way to pivot the wings while having heavy duty plasma transfer conduits running through them, or that the high mass of the warp coils made the design too unaerodynamic or something.
The nose carries a torpedo tube which we've seen fire various times. In ST III Kruge was informed that his ship was "ready to fire emergency tube" after it took a couple of hits from the Enterprise. I've never seen any evidence of any kind of aft facing torpedo tube such as the Vor'Cha or K'T'Inga has.
For detailed discussion of the Bird of Prey variants, see my article
on the subject.