Cheyenne Class

Universe :	Prime Timeline
Affiliation :	Federation
Class Name :	Cheyenne Class
Type :	Enhanced scientific/diplomatic explorer
Unit Run :	USS Cheyenne - Active NCC 71620 USS Ahwahnee [1] - Destroyed plus 134 others built in total. 106 have been lost in all.
Commissioned :	2345 - 2352, class remains in service
Dimensions :	Length : 394 m [2] Beam : 250 m Height : 113 m Decks : 20
Mass :	1,305,000 metric tons
Crew :	245
Armament :	2 x Type VIII phaser arrays, total output 7,500 TeraWatts 2 x Type 2 burst fire photon torpedo tube with 50 rounds
Defence Systems :	Standard shield system, total capacity 364,500 TeraJoules Standard Duranium Single hull. Standard level Structural Integrity Field
Warp Speeds (TNG scale) :	Normal Cruise : 6 Maximum Cruise : 9 Maximum Rated : 9.4 for 12 hours.
Strength Indices : (Galaxy class = 1,000)	Beam Firepower : 150 Torpedo Firepower : 800 Weapon Range and Accuracy : 145 Shield Strength : 135 Hull Armour : 10 Speed : 917 Combat Manoeuvrability : 4,180
Overall Strength Index :	381
Diplomatic Capability :	4
Expected Hull Life :	60
Refit Cycle :	Minor : 1 year Standard : 1 years Major : 25 years

Notes

The Cheyenne project was approved in 2338 as a scoutship to counterpart the New Orleans class Frigate and the upcoming Galaxy and Nebula class Explorers. As with most scouts the Cheyenne was intended to be somewhat faster than its contemporaries in order to allow it to travel out ahead of the main body of a fleet. In order to accomplish this, the Cheyenne was fitted with four nacelles in the pattern established by the much earlier Constellation class.

Initially, all did not go well with the Cheyenne. Starfleet has relatively limited experience with four nacelle designs, and a good deal of difficulty was experienced with the warp field geometry. Eventually these problems where overcome and the USS Cheyenne, launched in 2344, achieved a maximum speed of Warp 9.4 in trials. However, in December of 2344 the Galaxy project received new specifications calling for a top speed of Warp 9.6 [3]. With the prototype about to enter service and five more ships under construction, it was already too late to make any serious attempt to improve the top speed of the Cheyenne, so Starfleet was forced to bring a scout into service which was some 10% slower than the vessels it was supposed to work with.

Over the succeeding years several attempts where made to bring the speed of the Cheyenne up to Warp 9.7, but problems with the field geometry began to re-surface with alarming regularity. This culminated with a test on board the USS Ahwahnee; when a new computer control system was tried out the ship created a wormhole effect on its first test flight. Although the Ahwahnee survived and there where no casualties, the subspace stress caused severe cracking in the hull structure of all four nacelle struts. The ship was in spacedock for over a year while the struts where replaced. Starfleet suspended production of the class in 2352 after twenty five had been commissioned, mothballing the six ships under construction.

The Cheyenne has proved less than successful in service. Her relatively low speed has restricted her performance in her designed role, and she has been forced to operate in the role of a Frigate. She is not especially suited to this task - certainly not when compared to the New Orleans class which was purpose designed for the role. As a result the Cheyenne's have been given a very low priority for refits and upgrades, and have fallen considerably behind the rest of Starfleet in this respect.

With the advent of more modern scout ships such as the Intrepid, the Cheyenne was to be gradually retired from service. The increase in hostility in the alpha quadrant over the last ten years has led to this decision being reversed, and the Cheyenne's have played a small part in recent conflicts. The most notable contribution was Wolf 359, in which the USS Ahwahnee was destroyed by the Borg [4].

Colour key

References

#	Series	Season	Source	Comment
1			Star Trek Encyclopedia
2			Speculative	Calculated very approximately by comparing the overall length to the size of windows on a photograph of the Cheyenne model. Could well be off by 20% or more either way.
3			Star Trek The Next Generation Technical Manual	Page 57
4			Generic official information

Comments

The only appearence of the Cheyenne class to date is the USS Ahwahnee, which appeared in the Wolf 359 graveyard scene. The picture on the images page isn't great, but it's the only one I've ever been able to find. I've judged the ships dimensions length from this image, and assigned it as a scout because of the relatively small size.

The back story about problems with the four nacelle layout is a copy of the Constellation problems - since these are the only two Starfleet ships with four nacelles it seemed reasonable that they would both suffer from the same glitches. The stuff about the Galaxy class getting new speed requirements is from the TM, page 56/57, and it seemed reasonable that the Cheyenne would suffer accordingly if it was a slightly earlier ship.

Other than that it's mostly speculation. Since we haven't seen one single Cheyenne in service over the years, I guess they must be small in numbers and on their way out. If anybody has a better picture of this ship, I'd appreciate it if you'd post me a copy.

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Last updated : 12 Mar 2013

Source :	Speculative
Comment :	Calculated very approximately by comparing the overall length to the size of windows on a photograph of the Cheyenne model. Could well be off by 20% or more either way.

Book :	Star Trek The Next Generation Technical Manual
Comment :	Page 57