Sparcraft Internal Halyard Lock HL 10T (10 tons)

Manufacturer part #: 88081000072

Model	Equivalent Kevlar Wire	Equivalent ROD	Equivalent 1x19 wire	Equivalent Dyfor
HL 3T	10 T	-12	5/16 in	9/32 in
HL 5T	14 T	-17	3/8 in	5/16 in
HL 7T	20 T	-22	1/2 in	3/8 in
HL 10T	24 T	-30	9/16 in	1/2 in

Manufacturer part #: 88081000072

Model	A	B	C	D	E Ø	F	G Ø	H Ø	J Ø	K	L	Weight
3T	3 35/64 in 90 mm	4 in 102 mm	M29	3 3/8 in 86.5 mm	1 1/2 in 38 mm	3 21/32 in 93 mm	7/8 in 22 mm	1/2 in 12 mm	13/64 5 mm	4 1/2 in 114 mm	1/2 in 13 mm	6.22 oz 184 g
5T	5 in 128 mm	5 3/4 in 145 mm	M42	4 25/32 in 119 mm	2 1/8 in 54 mm	5 3/16 in 132 mm	1 1/4 in 32 mm	21/32 in 17 mm	5/16 in 8 mm	6 3/8 in 162 mm	11/16 in 18 mm	18.4 oz 546 g
7T	5 3/8 in 137 mm	6 5/32 in 156 mm	M45	5 3/8 in 131 mm	2 9/32 in 58 mm	5 9/16 in 141 mm	1 5/16 in 34 mm	3/4 in 19 mm	5/16 in 8 mm	6 13/16 in 173 mm	3/4 in 20 mm	23 oz 678 g
10T	5 1/2 in 163 mm	7 5/26 in 186 mm	M54	6 3/16 in 157 mm	2 23/32 in 69 mm	6 13/16 in 173 mm	1 13/16 in 46 mm	1 in 25 mm	3/8 in 9 mm	8 1/2 in 215 mm	15/16 in 24 mm	2.5 lb 1203 g

Manufacturer part #: 88081000072

Use
This system is mainly dedicated to flying forestays that once down reduce the head weights and the heel. Used also for mainsail, this locking device is widely fitted now on maxi yachts.

Functioning
When the sail is up, by pulling the halyard sharply, it locks or unlocks the hook.

Advantages
The high rig and halyard loads used by racing boats is transmitted into the rig, giving high mast compression loads. By locking the halyard directly onto the front head of the mast, the loads onto the mast are reduced by half.

Moreover, the removable Solent gives a possible gain in weight. Furthermore, with the halyard lock the sheaves at the head and the blocks at the step of the mast support consequently less load.

External/Internal fitting to the mast
The halyard lock can be equally fitted inside the mast or outside on an existing head attachment (for instance attachment for a removable baby stay).

Internally fitted lock : in this case, the external body of the lock is directly laminated (composite mast) or riveted/bolted onto the front head of the mast. The luff reaches an optimum length. The halyard runs down directly inside the mast. A large sheave can be fitted for smother operation.

Externally fitted lock : It can be fixed onto one head attachment with an articulated device (toggle, latching, Unibal ball or others). In this case, a small diameter sheave is integrated in the hooking system. The halyard can then run down inside or outside the mast.