This not only ensures the lifeboats are operational and will work if needed, but makes the crew proficient at launching them.
1	This	this	PRON	DT	Number=Sing|PronType=Dem	4	nsubj	4:nsubj|16:nsubj	_
2	not	not	PART	RB	_	4	advmod	4:advmod	_
3	only	only	ADV	RB	_	4	cc:preconj	4:cc:preconj	_
4	ensures	ensure	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	0:root	_
5	the	the	DET	DT	Definite=Def|PronType=Art	6	det	6:det	_
6	lifeboats	lifeboat	NOUN	NNS	Number=Plur	8	nsubj	8:nsubj|11:nsubj	_
7	are	be	AUX	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	8	cop	8:cop	_
8	operational	operational	ADJ	JJ	Degree=Pos	4	ccomp	4:ccomp	_
9	and	and	CCONJ	CC	_	11	cc	11:cc	_
10	will	will	AUX	MD	VerbForm=Fin	11	aux	11:aux	_
11	work	work	VERB	VB	VerbForm=Inf	8	conj	4:ccomp|8:conj:and	_
12	if	if	SCONJ	IN	_	13	mark	13:mark	_
13	needed	need	VERB	VBN	Tense=Past|VerbForm=Part	11	advcl	11:advcl:if	SpaceAfter=No
14	,	,	PUNCT	,	_	16	punct	16:punct	_
15	but	but	CCONJ	CC	_	16	cc	16:cc	_
16	makes	make	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	4	conj	4:conj:but	_
17	the	the	DET	DT	Definite=Def|PronType=Art	18	det	18:det	_
18	crew	crew	NOUN	NN	Number=Sing	16	obj	16:obj|19:nsubj:xsubj	_
19	proficient	proficient	ADJ	JJ	Degree=Pos	16	xcomp	16:xcomp	_
20	at	at	SCONJ	IN	_	21	mark	21:mark	_
21	launching	launch	VERB	VBG	VerbForm=Ger	19	advcl	19:advcl:at	_
22	them	they	PRON	PRP	Case=Acc|Number=Plur|Person=3|PronType=Prs	21	obj	21:obj	SpaceAfter=No
23	.	.	PUNCT	.	_	4	punct	4:punct	_
