Safehold Puzzle

[Parson]

I've puzzled over this for a while. I've read the appropriate passage a couple times but it's logic escapes me. Can anyone of you worthies enlighten me as to this:

In "Safehold" during the last scene in space David Weber has the humans play a trick on the aliens. When the aliens attack the human force, Weber has an equal number of ships escape as those who are fighting. I've never been able to figure out the logic of it. If the humans could keep the aliens from knowing that there were actually double the amount of ships there, why bother with elaborate ruse?

Parson will be indebted to anyone who can get this old brain to understand this.

 

[Timba]

Hi Parson,

Been awhile since I read that book so I have to admit I am not entirely sure what you are asking. However, I think you are asking why did they hide the true number ships and I always thought it was because they did not want the aliens to realize ships were escaping because in all prior instances when the aliens realized an escape was happening they followed.

If this is not really the question you are asking please reframe it for me as it is entirely possible I am missing a puzzle right in front of my face and would actually enjoy that being pointed out to me.

 

[Vertigo]

Timba, I think parson is more asking how it was done. I seem to recall having the same problem and I also seem to recall that I did eventually figure it out. Embarrassingly, and not very helpfully, I can no longer remember what I figured . I will take a look at it again and see if I can remember.

And I don't know how I missed this thread in the first place.

 

[Vertigo]

OK Here's my take on it.

First, the idea was for the colony ships to breakaway without the Gbaba noticing. IE so they would believe that destroying the main fleet would be destroying the very last human fleet.

In order to give the plan the best chance of success they needed to push the Gbaba scout ship further back so it wouldn't detect the switch.

As for the switch itself. It wasn't an equal number of ships escaping as fighting. I don't know how big Pei's fleet was but let's say he had 200 ships plus the 46 the would 'breakaway'. He also had another 46 ships with almost identical 'signatures' to the breakaway ships sat in full stealth. As the breakaway ships dropped out of hyper the stealthed ones immediately took their place. To the Gbaba nothing appeared to have changed. They needed to push the scout ship back as far as possible to ensure that. The key thing was that the Gbaba had to believe they had destroyed the entire and last human colonisation fleet.

So the Gbaba think there were only 246 ships that broke out of the blockade (see below), when actually there were 246 plus the hidden 46. When the colony ships drop out of hyper the hidden ships uncloak and presto there are still 246 ships. The Gbaba don't know there were another 46.

If you go on about four pages from the description of the breakaway you will find this:

After all, Breakaway had been Pei's personal brainchild, the sleight-of-hand intended to convince the Gbaba they'd successfully tracked down and totally destroyed mankind's last desperate colonization attempt. That was why the forty-six dreadnoughts and carriers which had accompanied the rest of his task force in stealth had not fired a missile or launched a fighter during the fight to break through the shell of capital ships covering the Gbaba scout globe around the Sol System.

It had been a stiff engagement, although its outcome had never been in doubt. But by hiding under stealth, aided by the background emissions of heavy weapons fire and the dueling electronic warfare systems of the opposing forces, they had hopefully remained undetected and unsuspected by the Gbaba.

The sacrifice of two full destroyer squadrons who'd dropped behind to pick off the only scout ships close enough to actually hold the escaping colony fleet on sensors had allowed Pei to break free and run, and deep inside, he'd hoped they'd manage to stay away from the Gbaba scouts. That despite all odds,all of his fleet might yet survive. But whatever he'd hoped, he'd never really expected it, and that was why those ships had stayed in stealth until this moment.

When the Gbaba navy arrived and it would; for all of their age, Gbaba ships were still faster than human vessels it would find exactly the same number of ships its scouts had reported fleeing Sol. Exactly the same number of ships its scouts had reported when they finally made contact with the fugitives once again.

And when every one of those ships was destroyed, when every one of the humans crewing them had been killed, the Gbaba would assume they'd destroyed all of those fugitives.

The key thing about it was that the 46 hidden ships remained hidden at all times. Which meant they could take no part in any fighting until the 46 colony ships had slipped away. Then they too their place and the Gbaba think they have destroyed the entire fleet.

As to why they couldn't just have sent the colony fleet off stealthed. I think the stealth isn't so effective up close. The gamble was that by hiding them in an unstealthed fleet breakout they would remain undetected so longer as they took no part in the actual fighting:

aided by the background emissions of heavy weapons fire and the dueling electronic warfare systems of the opposing forces, they had hopefully remained undetected and unsuspected by the Gbaba

 

[Timba]

Vertigo, I think you have it. I had actually forgotten the stealth piece but I agree with your assessment.

 

[Vertigo]

Phew, I'm glad you understood what I'd written. I think I was getting myself confused writing it

 

[Parson]

I'm back, busy weekend you know. But I believe you've hit it Vertigo. The piece I couldn't put together was why the ships couldn't slip away under stealth. But I believe that it was likely that the ships couldn't hyper out without leaving a trace, which the battle would confuse to the point that without a very careful analysis the Gbaba would believe that there had been no breakout to another spot for colonization.

Thanks Vertigo and Timba too.

 

[Vertigo]

You're very welcome Parson. I do remember very clearly spending some considerable time worrying at that one when I first read it. I seem to recall re-reading the opening section two or three times (something I very rarely do!)

 

[Timba]

Not sure what my babbling added other than to perhaps inspire Vertigo to provide his fine explanation but you are certainly welcome Parson.

 

[Parson]

Not sure what my babbling added other than to perhaps inspire Vertigo to provide his fine explanation but you are certainly welcome Parson.

I was thanking you for trying, reading my post, and for being involved in the discussion.