From a sketch in the Red Book: the Ger/CB/1907

There are no specifications, but there is a scale drawing of what I interpret to be a German battlecruiser. I am reasonably certain of the intent with respect to armour and guns. The result is a fast battleship sort of battlecruiser, with 8-12in BLR and 12-6in QF guns. The length is 600ft and the citadel is obviously 360ft. Going on that basis, I created a Springsharp design for a ships with one turret on the forecastle, one aft of the first funnel, facing forward, and two aft, with one in the superfiring position. This is the Springsharp report:

Ger/CB/1907, Germany Battlecruiser laid down 1907

Displacement:
 23,192 t light; 24,145 t standard; 26,600 t normal; 28,564 t full load

Dimensions: Length overall / water x beam x draught
 600.00 ft / 600.00 ft x 88.00 ft x 29.00 ft (normal load)
 182.88 m / 182.88 m x 26.82 m  x 8.84 m

Armament:
      8 - 12.00" / 305 mm guns (4x2 guns), 864.00lbs / 391.90kg shells, 1907 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 1 raised mount aft - superfiring
      12 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1907 Model
   Quick firing guns in casemate mounts 
   on side, evenly spread
   12 guns in hull casemates - Limited use in heavy seas
 Weight of broadside 8,208 lbs / 3,723 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 11.0" / 279 mm 360.00 ft / 109.73 m 9.00 ft / 2.74 m
 Ends: 5.00" / 127 mm 240.00 ft / 73.15 m 12.00 ft / 3.66 m
 Upper: 8.00" / 203 mm 360.00 ft / 109.73 m 8.00 ft / 2.44 m
   Main Belt covers 92 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  2.00" / 51 mm 360.00 ft / 109.73 m 28.00 ft / 8.53 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 11.0" / 279 mm 8.00" / 203 mm  11.0" / 279 mm
 2nd: 6.00" / 152 mm 6.00" / 152 mm  6.00" / 152 mm

   - Armour deck: 3.00" / 76 mm, Conning tower: 11.00" / 279 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 4 shafts, 85,607 shp / 63,863 Kw = 27.00 kts
 Range 5,400nm at 15.00 kts
 Bunker at max displacement = 4,419 tons

Complement:
 1,040 - 1,353

Cost:
 £2.355 million / $9.418 million

Distribution of weights at normal displacement:
 Armament: 1,026 tons, 3.9 %
 Armour: 8,438 tons, 31.7 %
    - Belts: 3,128 tons, 11.8 %
    - Torpedo bulkhead: 746 tons, 2.8 %
    - Armament: 2,194 tons, 8.2 %
    - Armour Deck: 2,159 tons, 8.1 %
    - Conning Tower: 211 tons, 0.8 %
 Machinery: 4,864 tons, 18.3 %
 Hull, fittings & equipment: 8,864 tons, 33.3 %
 Fuel, ammunition & stores: 3,408 tons, 12.8 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   31,618 lbs / 14,342 Kg = 36.6 x 12.0 " / 305 mm shells or 4.3 torpedoes
 Stability (Unstable if below 1.00): 1.16
 Metacentric height 5.4 ft / 1.7 m
 Roll period: 15.8 seconds
 Steadiness - As gun platform (Average = 50 %): 55 %
   - Recoil effect (Restricted arc if above 1.00): 0.51
 Seaboat quality  (Average = 1.00): 1.10

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.608
 Length to Beam Ratio: 6.82 : 1
 'Natural speed' for length: 24.49 kts
 Power going to wave formation at top speed: 56 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): -2.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  27.00 ft / 8.23 m
    - Forecastle (20 %): 25.00 ft / 7.62 m
    - Mid (67 %):  25.00 ft / 7.62 m (17.00 ft / 5.18 m aft of break)
    - Quarterdeck (15 %): 17.00 ft / 5.18 m
    - Stern:  17.00 ft / 5.18 m
    - Average freeboard: 22.52 ft / 6.86 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 114.4 %
  - Above water (accommodation/working, high = better): 162.4 %
 Waterplane Area: 38,907 Square feet or 3,615 Square metres
 Displacement factor (Displacement / loading): 101 %
 Structure weight / hull surface area: 156 lbs/sq ft or 760 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.58
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent