WesWorld

Summary

Thomson-MEE YPSBM "Mainsail"
Type: Production surface-search Y-range for capital ships and cruisers
Set Range: Classified
Date in Service: 1936
Notes: Versatile enough to detect aircraft at fifty miles or more in certain conditions. Similar to US CXAM or Seetakt. Atlantean-made.

Thomson-MEE YPTBM "Moonraker"
Type: Production air-search Y-range for capital ships and cruisers
Set Range: Classified
Date in Service: 1936
Notes: Air-warning radar. Functional equivalent to YPSBM. Atlantean-made.

Thomson-MEE YQAM "Starfield"
Type: Airborne Y-range set for airships
Set Range: Classified
Date in Service: 1936
Notes: Atlantean-made; installed on airship Capitan Prat.



SisDef: Design, Production, Etc.
SisDef (Sistemas Defensas) was founded in 1939 as a subsidiary of ASMAR and ENAER to provide components for electric, electronic, and related gear. Among SisDef's responsibility is the local production of naval radar and gunnery computers, which is carried out through an agreement with Atlantean radar manufacturers, who provide designs and key production assistance.

In 1939, SisDef produced only two complete radar suites (two Type 101s and two Type 200s), while in 1940, production is expected expanded substantially. By 1943, SisDef was selling dradis units on the export market to Brazil and the Philippines.

SisDef Type 101 Mainsail-II
Description: Production surface-search Y-range for capital ships and cruisers. Furnishes range and bearing of surface vessels and aircraft, and can be used for control of interception. Set has both "A" and SAS scopes, provisions for operating with remote SAS's and for FES connections.
Performance: Reliable maximum range, with antenna at 100', is 100 miles on medium bombers at 1,000' altitude. Range accuracy is ± 100 yards. Azimuth accuracy, ± 3°. There is no elevation control.
Date in Service: 1940
Transportability: Not air transportable
Installation: Mainsail-II has 10 components weighing approximately 5000 lbs. Heaviest unit (2400 lbs.) is the antenna assembly. Antenna measures 15' x 16'9". Antenna should be 100 ft. or more above water.
Notes: The Type 101 Mainsail-II dradis is based on the earlier Atlantean-designed YPSBM dradis. The Type 101 substitutes a rotating antenna for better coverage, and adds a CRT-based Signal Autoplot Scope. The Type 101 also has the capability to identify Friendly Echo Signature devices. (Type 101 is based on SK.)

SisDef Type 200 Moonraker
Description:
Performance:
Date in Service: 1936 (Atlantean service)
Transportability:
Installation:
Notes: Type 200 Moonraker is a system based off the Type 100 / YPSBM Mainsail dradis. The Type 100 has several key changes which offer better performance against aircraft at all ranges. The Type 200 operates at a different wavelength, and has several changes intended to help measure angles-above-surface, which permits the dradis operator to roughly estimate an aircraft's altitude. (Type 100 and Type 101 dradis sets offer superior resolution at short and intermediate ranges, but cannot measure altitudes.)

SisDef Type 102 Cactus
Description: Microwave search set installed on destroyers and larger ships to search for enemy surface ships, to coordinate attack by surface vessels, and to aid in navigation. Furnishes range and bearing on SAS and "A" scopes, with provision for use with FES.
Performance: Reliable maximum range is 15 miles on large ships; with antenna height of about 100 feet. Range accuracy is ± 100 yds. Azimuth accuracy: ± 2°.
Date in Service: 1941
Transportability: Complete shipment includes spares and testing equipment, and is crated in 15 units weighing about 4289 lbs. Largest package is 13'4" x 12" x 10" and weighs 359 lbs. Heaviest package (1425 lbs.) is 28" x 41" x 80".
Installation: 5 components weighing approximately 2200 lbs. Heaviest unit (1180 lbs.) is the transmitter-receiver -- 737/8" x 34" x 223/8". Antenna, which weighs 350 lbs. with pedestal and measures 44" x 491/2" in diameter, should be mounted as high as possible, preferably more than 100 feet above water and above adjacent superstructure.
Notes: (Similar to SG)

SisDef Type 103 Baby Cactus
Description: Microwave search set installed on destroyers and similarly-sized ships to search for enemy surface ships, to coordinate attack by surface vessels, and to aid in navigation. Furnishes range and bearing on SAS and "A" scopes, with provision for use with FES.
Performance: Reliable range is 15 miles on large ship, with antenna height of about 100 ft. Range accuracy is ± (1% + 100 yds.) Azimuth accuracy is ± 2°.
Date in Service: 1942
Transportability: Shipment includes spares for approximately 1500 hours. Complete shipment is packed in 13 boxes (including spare parts), the largest of which is 33" x 35" x 42". When crated, the shipment weighs 2200-2300 lbs.
Installation: 10 components weighing a total of approximately 900 lbs. Heaviest unit (300 lbs.) is the motor generator--161/4" x 401/4" x 131/2". Antenna, which weighs 125 lbs. and measures 361/4" high by 303/4" in diameter, should be mounted as high as possible, with transmission line not exceeding 50 ft. in length.
Notes: Type 103 Baby Cactus is a lightened variant of the Type 102 Cactus. It was developed for use aboard destroyers (Similar to SF)

Type 201 Invunche
Description:
Performance:
Date in Service: 1940
Transportability:
Installation:
Notes: Similar to SC-270

Fire Control Radars

ASMAR/SisDef Mk37A "Sorcery" Gunnery Computer
The Mk37A gunnery computer was the first gunnery computer manufactured in Chile, being originally built by ASMAR's Technical Electronics Division, which became part of SisDef in 1939. The Mk37A was originally developed for installation on the heavy cruiser CNS Constitucion, first supplementing and eventually supplanting the traditional manual naval gunnery methods then in use. By mid-1939, the Mk37A could receive and process data from a wealth of both human and electronic inputs, calculating (among other things) the course and speed of the firing ship, the course, speed, and range of the target, the ballistics of the guns, and other conditions that would affect gunnery accuracy. In 1941, the Mk37A computer was modified into the Mk37A-GC1, which further evaluated the motion of the ship using gyroscopes, and automatically steered the gun turrets and selected barrel elevations, and then discharged the guns automatically when the conditions were right.

In 1941, following the Mk37A-GC1 upgrade, Constitucion demonstrated the capabilities of the system by firing six salvos at a target barge while conducting a series of maneuvers at 33 knots. The gunnery computer correctly adjusted the guns as range and bearing changed, and placed all the rounds fired within a 55-meter radius of the target barge.

ASMAR/SisDef Mk37B "Clear Sky" Gunnery Computer
The Mk37B "Clear Sky" was a modification of the Mk37A gunnery computer which was intended to control 130mm, 110mm, and 76.2mm anti-aircraft batteries from a central location. For this purpose, the Mk37B added additional elements to the Mk37A, particularly in the manner of calculating the timing on shell fuses and introducing a vertical element. However, the Mk37B system did not offer significant advantages until several years after its introduction when it would be mated with centimetric fire-control radar.

SisDef Mk41 "Nevada" Gunnery Computer
Design of the Mk41 Gunnery Computer began at Thomson-MEE in 1939 in Atlantis to develop a comprehensive gunnery computer that could control both main-battery fire against sea and land targets as well as directed AA battery fire. The Atlantean designers also wished to downsize the previous heavy gunnery computers, and successfully managed this feat. The first Mk41s emerged from MEE in March 1941 and entered production at SisDef some months later.