RN Nuclear NIGS ship

[JFC Fuller]

Oil-fired superheat lets you run superheated steam, which PWRs can't do, so gets you theoretically better performance from your neutrons but you're dependent on having oil fuel for good performance. It does seem to be what the Soviets did, and is probably the best way to do CONAS.

Separate boilers feeding the same turbines requires that the turbines run on saturated steam, which is an inefficient way to burn oil fuel and not great for turbines. Nuclear plants deal with this because they have to, and because fuel efficiency is less of a concern for them. AFAIK this is how the West thought the Soviet CONAS plants worked, but it seems to just be bad.

Entirely separate oil-fired and nuclear plants geared onto the same shaft adds a whole bunch of weight and complexity, but makes the plant design and operation effectively independent. At this point, you've just got an oil-fired boost plant. CONAG is a much lighter way to do that.

If the RN was talking about a 20,000 shp nuclear plant and a 20,000 shp steam plant, I suspect they were thinking in terms of the third option.

I can't say exactly how the 50/50 CONAS plant would have worked but I am certain that it was an option considered only briefly under a much wider nuclear propulsion study. The study that was ongoing at the time ultimately concluded that CONAG would be the optimum solution for a 75,000 SHP plant for guided missile destroyers. Specifically, a single reactor delivering 60,000 SHP and two 7,500 SHP G6 gas turbines to provide emergency power, rapid start-up and boost from 80% power to 100% power. The logic was:

1. The nuclear part of the system was heavy, anything to make it lighter was good, e.g. having alternative emergency power meant only one reactor was needed and using the Gas Turbines for boost meant that the single reactor could be smaller and lighter
2. The study assumed the ship had a double bottom, the double bottom would have to be filled with liquid anyway so that liquid may as well be fuel
3. Like conventional boilers, nuclear reactors were slow to raise steam, adding gas turbines solved for this, allowing the ship to get underway faster

As you point out, PWRs couldn't produce superheated steam. There was a view that a gas cooled reactor, specifically a CO2 cooled, graphite moderated reactor, would offer a lighter weight solution that could produce steam comparable to modern oil fired boilers. This would require more work but might be a practical proposition in the future. The added advantage of the gas cooled reactor was that further development would support a path to a gas cooled reactor connected directly to a closed cycle gas turbine, that being considered the ultimate power reactor at the time. The downside was the need for much greater pumping power to circulate the coolant than was necessary for a PWR.

Note that this was all 1956-58.

 

[Yellow Palace]

Specifically, a single reactor capable of delivering 60,000 SHP and two 7,500 SHP G6 gas turbines to provide emergency power, rapid start-up and boost from 10% power to 100% power.

I suspect it didn't hurt that a 60,000 shp reactor is also a convenient size for an aircraft carrier plant. Whether anyone wrote that down at the time is another matter....

 

[Tzoli]

I've acquired the ADM 220/2179 (Sub title: PROPOSALS FOR A LONG RANGE (UP TO 100 n.m.) G.M. SYSTEM OF HIGH CAPACITY) document and currently typing it into a word so you guys could read it. Sadly it has not a single mention of NIGS or SIGS though it describes basically the requirements and desires which resulted in the start of developing the NIGS and SIGS. It maybe be of interest to some of you but looks like it is not useful to me at all. No data on the missile, the launchers or the ship proposals to carry it. Only a vague mention that the first system should be tested on a light fleet carrier.
The document dated 1955 and based on Friedman's description it should had contained the important NIGS warship proposals...

Does the missile project names Red Shoes and Red Duster rings a bell for anybody?

 

[Hood]

I'm not too surprised, the date looked a little early for NIGS, even predates Blue Envoy.

Red Shoes = Thunderbird
Red Duster = Bloodhound

 

[Tzoli]

Yeah I've noticed...
And reading the description for the launchers:

11. LAUNCHERS

It is strongly recommended that fixed zero length launchers should be used in view of the extra weight, complexity and power requirements of the trainable ones. This subject to the provisos outlined in the section on low altitude attack.

It is recommended that the ship should be able to launch at a rate of up to about 10 per minute and that this be obtained by using about 6 launchers, each supplied from a warehouse type stowage.

In order to meet possible changes in future missile dimensions, it is desirable that as far as possible the greatest flexibility should be used in the design of missile stowage and handling equipment.

This basically describes the GW 70-81 design series. Which had various (2-4-5-6-10 single) Stage 1 3/4 missile launchers.

 

[JFC Fuller]

ADM 220/2179 immediately predates the RN adopting Blue Envoy as its next generation long range SAM. Blue Envoy was adopted instead to meet the same basic requirement. NIGS came about because of the cancellation of Blue Envoy. I’m skeptical that the RN would have ultimately used Blue Envoy had it not have been cancelled, it was atrociously designed from the perspective of ship fitting.

 

[Tzoli]

Does anybody have Document ID's which contain these drawings?