You are not logged in.

Peruvian Plans - 1948

  • 1
  • 2

Brockpaine

The Shadow

Posts: 15,109

  • Send private message

21

Thursday, February 9th 2017, 2:43am

Quoted from "BruceDuncan"

It is quite probable I am over-estimating the tonnage for radar on the refits; but I haven't any good information to go on for the weights (or mass) of Dutch radars and associated equipment. I figure that it may also take into account space/weight for generator sets, CIC, and things of that sort.

That's fair enough. Let me provide what's basically a quick-and-dirty proposal, based on the process I've used for Chile / France / Russia. Keep in mind that I'm merely outlining how I would approach it, and you could tweak the weights a bit if you want.

I always start by trying to fill out the application I need, and pull together some broad categories. So, for instance, my application is: I need a fire-control radar for some destroyers that have 130mm DP guns, and some cruisers that have either 130mm or 100mm DP secondaries. Similarity of application high. Use the same radar for both purposes. Thus, I create the Sisdef Type 301 "Boldo" fire-control radar, which is distinct from the Pehuén fire-control radar that I use for the 20cm+ applications.

So, getting around to the proposed radars:

Quoted

CHRONOLOGICAL LISTING
Key:
- The 'Type' indicates the set's listing according to the radar chronology. Lower numbers were acquired earlier.
- The M-number indicates the year the set was acquired.
- The name is a convenient descriptor to call it by. Search sets are named after Peruvian rivers. Fire-control sets are named after Peruvian mountains.

Obviously, these names would be Peruvian names only. I "fleshed them out" with names and designations in order to keep things straight when talking about those varied applications...

Type 1 M34 Ucayali: Metric search set. Designation applied to the Bharati-provided radar used briefly during the Peruvian Civil War. Also used aboard Almirante Grau as originally commissioned.

Type 2 M44 Marañón: Metric search set. Unknown origin. Set used aboard the Libertad-class destroyers in 1943-1944. 10t total weight (3t antenna).

Type 3 M45 Putumayo: Centimetric air-search set. Dutch origin? Set used aboard the Montero-class destroyers upon completion in 1945. Total system weight:
- 5 tons on destroyers (using 1t A antenna)
- 8 tons on cruisers and larger (using 4t B antenna).

Type 4 M45 Yavarí: Centimetric surface-search set. Dutch origin? Set used aboard the Montero-class destroyers upon completion in 1945. Total system weight:
- 5 tons on destroyers (using 1t A antenna)
- 8 tons on cruisers and larger (using 4t B antenna).

Type 5 M45 Huallaga: Navigational / basic surface search set. Dutch origin? Set used aboard the Montero-class destroyers upon completion in 1945. Total system weight: 3 tons regardless of application (350kg antenna)

Type 6 M48 A/B/C Huascarán: Fire-control set of (Dutch?) origin intended for guns of 150mm up to 305mm size. Used on refits for Callao, Almirante Grau, Almirante Villar, Ancash-class and Cajamarca-class. Total system weight:
- 10 tons on ships of 7k - 11k tons (using the 2-ton A antenna)
- 12 tons on ships of 11k - 20k tons (using the 4-ton B antenna)
- 14 tons on ships of 20k tons or more (using the 6-ton C 'Grande' antenna)

Type 7 M48 Yerupajá: Fire-control set of (Dutch?) origin intended for dual-purpose guns of between 100mm and 130mm. Used as primary fire-control on destroyers with dual-purpose guns from 1948 onward, and for secondary batteries on ships of cruiser size and larger. Total system weight:
- 5 tons on destroyers as main battery FC
- 5 tons on cruisers and capital ships as secondary battery FC

Type 8 M48 Urubamba: Heavy-duty surface and low-altitude air search set of (Dutch?) origin. Total system weight:
- 12 tons on ships of 7k - 11k tons (using the 4-ton A antenna)
- 13.5 tons on ships of 11k - 20k tons (using the 6-ton B antenna)
- 15 tons on ships of 20k tons or more (using the 8-ton C 'Grande' antenna)

Type 9 M48 Mantaro: Air search set of (Dutch?) origin. Total system weight:
- 10 tons on ships of 7k - 11k tons (using the 4-ton A antenna)
- 12.5 tons on ships of 11k - 20k tons (using the 6-ton B antenna)
- 15 tons on ships of 20k tons or more (using the 8-ton C 'Grande' antenna)


So then, for example, the Montero currently has 13t earmarked for radar, with an air search, surface search, and navigational set particularly earmarked. Thus we arrive at the Model 1945 Destroyer Suite:

Quoted

Model 1945 Destroyer Suite: (Montero-class)
- Type 3 Putumayo air search set: 5t
- Type Type 4 Yavarí surface search set: 5t
- Type 5 Huallaga navigational set: 3t
Total weight, 13 tons


So then, in theory, all of the 1948 cruiser rebuilds would get the same radar suite, but weights would differ slightly as the larger ships receive bigger antennas (with better options for range and resolution). To whit:

Quoted

Model 1948 Cruiser Suite:
Ancash and Cajamarca:
- Type 8 M48 Urubamba surface search set: 12t
- Type 9 M48 Mantaro air search set: 10t
- Type 6 M48A Huascarán main battery fire control: 2 sets, 10t each
- Type 7 M48 Yerupajá secondary battery fire control: 2 sets, 5t each
- Type 5 Huallaga navigational set: 3t
TOTAL: 55 tons

Callao and Almirante Grau:
- Type 8 M48 Urubamba surface search set: 13.5t
- Type 9 M48 Mantaro air search set: 12.5t
- Type 6 M48B Huascarán main battery fire control: 2 sets, 12t each
- Type 7 M48 Yerupajá secondary battery fire control: 2 sets, 5t each
- Type 5 Huallaga navigational set: 3t
TOTAL: 63 tons


...and so on and so forth. The weights are a little different than the ones that I use for comparative gear, but that's because I added in distinct antenna sizes for different weight classes of ship.

So, in comparison, the Constitución gets the following dradis arrangement:

Quoted


- SAGEM DRBV-11 Moselle PA search radar (1 radar, 15 tons)
- Sisdef Type 104.1 "Cactus/5" sentry radar (1 radar, 10 tons)
- Sisdef Type 300.2g "Pehuén" main battery fire-control radars (2 radars, 15 tons)
- Sisdef Type 301.3.2 "Boldo" secondary battery fire-control radars (2 radars, 10 tons)
- Sisdef Type 103.1 "Nalca" navigational surface and air search radar (1 radar, 2 tons)

Brock's note: Cactus and Moselle radars have some overlap in capabilities: they are both air- and surface-search radars. However, Moselle PA's design makes it useful for very fast, broad sweeps of air and surface, tracking a lot of targets and weeding out the clutter; while Cactus/5 is a monopulse radar that can track select targets with much higher accuracy.


For further reference, here's the name list I generated:

Quoted

== SEARCH SETS (RIVERS) ==
Ucayali
Marañón
Putumayo
Yavarí
Huallaga
Urubamba
Mantaro
Amazon
Apurímac
Napo

== FIRE CONTROL SETS (MOUNTAINS) ==
Huascarán
Yerupajá
Coropuna
Huandoy
Ausangate
Huantsán
Chopicalqui
Chinchey
Ampato
Palcaraju


Last but not least, the Dutch Province-class CLs, built in 1945, have:

Quoted

50 tons for RDF sets (2 main directors, 4 secondary directors, surface search and aerial search)

So that is somewhat comparable to the Model 1948 Cruiser Suite. The Dutch have managed to squeeze out two more secondary directors and lose five tons, but it stands to figure that the Dutch keep all their best gear for themselves.
  • 1
  • 2