page_title: Spanish submarine Peral
section_title: Construction
hierarchical_section_title: Spanish submarine Peral / Conception / Construction
caption_attribution_description: English: Isaac Peral's submarine: turret (Naval Museum, Cartagena) Español: Torreta del submarino de Peral (Museo Naval, Cartagena)
context_page_description: Peral was the first electric battery-powered submarine, built by the Spanish engineer and sailor Isaac Peral for the Spanish Navy. The first fully capable military submarine, she was launched 8 September 1888. She had one torpedo tube and an air regeneration system. Her hull shape, propeller, periscope, torpedo launcher and cruciform external controls anticipated later designs. Her underwater speed was 3 kn. With fully charged batteries, she was the fastest submarine yet built, with underwater performance levels that matched those of First World War U-boats for a very short period, before her batteries began to drain. For example, the SM U-9, a pre-war German U-boat built in 1908, had an underwater speed of 8.1kn, and an underwater range of 150 km at 5.8kn, before having to resurface to recharge her batteries. Although advanced in many ways, Peral lacked a means of charging batteries while underway, such as an internal combustion engine, thus had a very limited endurance and range. In June 1890, Peral's submarine launched a torpedo while submerged. It was also the first submarine to incorporate a fully reliable underwater navigation system.
context_section_description: On 25 April 1887, the submarine's construction was finally approved by the government; the keel was laid down on La Carraca on 7 October, although work did not start until two weeks later. Nevertheless, the submarine had already undergone a number of modifications: Peral's original 1885 model conceived of a 61-ton submarine, 18.8 m (62 ft) long, with a beam of 2.52 m (8.3 ft) and a single 40 shp (30 kW) electric motor for a single shaft. The submarine Peral began in 1887 had a length of more than 22 m (72 ft), a beam of 2.87 m (9.4 ft), a draft of 2.76 m (9.1 ft), two 30 shp (22 kW) electric motors geared to twin screws, and a displacement of 77 tons surfaced and 85 submerged.
  Air regeneration in the interior of the submarine was accomplished by an auxiliary 6 hp (4 kW) engine, which passed the air through a sodium hydroxide purifier to eliminate CO₂ exhaled by the crew. In addition, the pump injected oxygen when needed. The same engine which circulated air also drove the bailing pump.
  The submarine dived by means of the "depth's device" which drove two shafts of vertical axes located at both ends of the hull, moved by two 4 hp (3 kW) electrical motors to submerge or surface, and to maintain horizontal stability submerged. The ballast tanks had a storage capacity of 8 tons, and were used to stabilize the submarine. In order to navigate, Peral used a bronze magnetic needle installed in the ceiling of the turret. The design avoided any electrical interference. He also devised a periscope, a fixed tube on the turret; by using a series of prisms, it projected the outside world to within the submarine.
  The engine-cooling system consisted of forcing compressed air stored in the submarine over the engines, and though the original project had needed 430 accumulators, the final project installed 613 with a weight of 50 kg (110 lb). The total weight of the batteries was around 30 tons.
  The top speed varied with the charge of the batteries. With one-quarter charge, the submarine was able to reach 4.7 kn (8.7 km/h; 5.4 mph), one-half 6.9 kn (12.8 km/h; 7.9 mph), three-quarters 8.9 kn (16.5 km/h; 10.2 mph), knots, completely charged 10.9 kn (20.2 km/h; 12.5 mph). The range of the boat again depended on battery charge level; Peral calculated his original submarine could reach 132 nmi (152 mi; 244 km) at a speed of 6 kn (11 km/h; 6.9 mph). With no means of charging batteries while underway, such as an internal combustion engine, endurance and range were limited.
  One of the original features of Peral was an underwater lamp, which enabled the crew to search the sea bottom. The searchlight had a range of 150 m (490 ft).
  The submarine was single-hulled, and the ballast tanks were located at the bottom of the hull, underneath the torpedo tube. This single torpedo tube was the only weapon in the submarine, with two watertight doors on each end so the submarine could launch a torpedo submerged. Mechanisms used for reloading were simple and fast, and the submarine had three reserves. This was almost identical to the torpedo launchers used in submarines since then. In order to avoid expenses, the torpedoes Peral launched during the trials were borrowed from torpedo boats, two from Retamosa and one from Barceló.
caption: Turret detail
exif: {"Image ImageDescription": "", "Image Make": "Canon", "Image Model": "Canon PowerShot SX500 IS", "Image Orientation": "Rotated 90 CW", "Image XResolution": "180", "Image YResolution": "180", "Image ResolutionUnit": "Pixels/Inch", "Image DateTime": "2015:01:17 19:38:23", "Image YCbCrPositioning": "Co-sited", "Image ExifOffset": "246", "GPS GPSVersionID": "[2, 3, 0, 0]", "Image GPSInfo": "4938", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "180", "Thumbnail YResolution": "180", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "5620", "Thumbnail JPEGInterchangeFormatLength": "4746", "EXIF ExposureTime": "1/20", "EXIF FNumber": "17/5", "EXIF ISOSpeedRatings": "400", "EXIF SensitivityType": "Standard Output Sensitivity and Recommended Exposure Index", "EXIF ExifVersion": "0230", "EXIF DateTimeOriginal": "2015:01:17 19:38:23", "EXIF DateTimeDigitized": "2015:01:17 19:38:23", "EXIF ComponentsConfiguration": "YCbCr", "EXIF CompressedBitsPerPixel": "3", "EXIF ShutterSpeedValue": "69/16", "EXIF ApertureValue": "113/32", "EXIF ExposureBiasValue": "0", "EXIF MaxApertureValue": "113/32", "EXIF MeteringMode": "Pattern", "EXIF Flash": "Flash fired, auto mode, red-eye reduction mode", "EXIF FocalLength": "43/10", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "4608", "EXIF ExifImageLength": "3072", "Interoperability InteroperabilityIndex": "R98", "Interoperability InteroperabilityVersion": "[48, 49, 48, 48]", "Interoperability RelatedImageWidth": "4608", "Interoperability RelatedImageLength": "3072", "EXIF InteroperabilityOffset": "4860", "EXIF FocalPlaneXResolution": "2304000/121", "EXIF FocalPlaneYResolution": "1728000/91", "EXIF FocalPlaneResolutionUnit": "2", "EXIF SensingMethod": "One-chip color area", "EXIF FileSource": "Digital Camera", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF DigitalZoomRatio": "1", "EXIF SceneCaptureType": "Standard", "EXIF CameraOwnerName": ""}