To clarify, what exactly do you mean by shipyard? There are a few possible interpretations, such as:
1) Medium fleet base, important but not indespensible. Probably coupled with minor shipyards
2) Major fleet base, of similar size and strategic role to Singapore IOTL
3) Minor Construction Hub, not producing to much of importance or size but at least decently sized by the standards of the time and place
4) Major constuction base, producing basically whatever it can possibly produce.