Try using this:
<EffectType>Military</EffectType>
<Scope>AreaEffect</Scope>
<Target>
<TargetType>Colony</TargetType>
</Target>
<BonusType>Flat</BonusType>
<Value>5</Value>
instead of targeting the shipyard. This is more or less what the 'Helpful Dust' event uses, and I'm fairly certain that you're trying to do essentially the same thing as that event does.
I'm not sure it'll work as I haven't tried it, but this is my guess at what would work.