CG-45 Chelan 1928 Camden NJ
CG-46 Pontchartrain 1928 Camden NJ
CG-47 Tahoe 1928 Camden NJ
CG-48 Champlain 1928 Boston MA
CG-49 Mendota 1928 Boston MA
CG-50 Itasca 1929 Norfolk VA
CG-51 Sebago 1929 Norfolk VA
CG-52 Saranac 1929 Norfolk VA
CG-53 Shoshone 1929 Bremerton WA
CG-54 Cayuga 1929 Bremerton WA
The 250-foot class cutters were designed by the Coast Guard and were, in many respects, modernized 240-footers. Captain Q.B. Newman, USCG, designed its innovative turbine-electric-drive power plant, which developed an amazing 3,350 shp. These were the first to have alternating current, and a synchronous motor for propulsion. The whole ship ran off the main turbine. The auxiliary generators were tied into the main generator electrically, after sufficient speed was attained. At that point, no steam was required to drive the turbines on the auxiliary generators. The propulsion plant achieved remarkable efficiency. The counter stern and plumb bow of the older class had given way to the flared stem and cruiser stern. These features were an attempt to improve sea qualities over the 240-foot class, particularly to eliminate the heavy shocks common in the North Atlantic Ice Patrol
Lake Class, United States Coast Guard Cutter laid down 1929
Displacement:
1,468 t light; 1,513 t standard; 1,845 t normal; 2,111 t full load
Dimensions: Length overall / water x beam x draught
250.00 ft / 241.40 ft x 42.00 ft x 13.00 ft (normal load)
76.20 m / 73.58 m x 12.80 m x 3.96 m
Armament:
1 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1929 Model
Breech loading gun in deck mount
on centreline forward
1 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1929 Model
Breech loading gun in deck mount
on centreline aft
2 - 2.20" / 55.9 mm guns in single mounts, 5.32lbs / 2.41kg shells, 1929 Model
Anti-aircraft guns in deck mounts
on side, all forward, all raised mounts - superfiring
Weight of broadside 87 lbs / 39 kg
Shells per gun, main battery: 150
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 1.50" / 38 mm 106.79 ft / 32.55 m 7.78 ft / 2.37 m
Ends: 1.50" / 38 mm 132.19 ft / 40.29 m 7.78 ft / 2.37 m
2.42 ft / 0.74 m Unarmoured ends
Main Belt covers 68 % of normal length
- Torpedo Bulkhead:
1.50" / 38 mm 106.79 ft / 32.55 m 11.31 ft / 3.45 m
Machinery:
Oil fired boilers, steam turbines,
Electric motors, 1 shaft, 3,850 shp / 2,872 Kw = 17.30 kts
Range 11,700nm at 12.00 kts
Bunker at max displacement = 599 tons
Complement:
140 - 183
Cost:
£0.308 million / $1.232 million
Distribution of weights at normal displacement:
Armament: 11 tons, 0.6 %
Armour: 185 tons, 10.0 %
- Belts: 118 tons, 6.4 %
- Torpedo bulkhead: 67 tons, 3.6 %
- Armament: 0 tons, 0.0 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 118 tons, 6.4 %
Hull, fittings & equipment: 1,034 tons, 56.0 %
Fuel, ammunition & stores: 377 tons, 20.5 %
Miscellaneous weights: 120 tons, 6.5 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
6,690 lbs / 3,034 Kg = 107.0 x 5.0 " / 127 mm shells or 3.3 torpedoes
Stability (Unstable if below 1.00): 1.15
Metacentric height 1.8 ft / 0.5 m
Roll period: 13.3 seconds
Steadiness - As gun platform (Average = 50 %): 90 %
- Recoil effect (Restricted arc if above 1.00): 0.05
Seaboat quality (Average = 1.00): 1.70
Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.490
Length to Beam Ratio: 5.75 : 1
'Natural speed' for length: 15.54 kts
Power going to wave formation at top speed: 54 %
Trim (Max stability = 0, Max steadiness = 100): 53
Bow angle (Positive = bow angles forward): 10.00 degrees
Stern overhang: 5.20 ft / 1.58 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 19.30 ft / 5.88 m
- Forecastle (28 %): 14.90 ft / 4.54 m
- Mid (50 %): 12.50 ft / 3.81 m
- Quarterdeck (28 %): 12.30 ft / 3.75 m
- Stern: 14.90 ft / 4.54 m
- Average freeboard: 14.20 ft / 4.33 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 64.8 %
- Above water (accommodation/working, high = better): 114.0 %
Waterplane Area: 6,423 Square feet or 597 Square metres
Displacement factor (Displacement / loading): 294 %
Structure weight / hull surface area: 98 lbs/sq ft or 477 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.70
- Longitudinal: 5.60
- Overall: 1.91
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is adequate
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather