Rigging Back to Projects
The 10M has a masthead single spreader rig with in-line and forward lowers. The mast was made for Pearson by Soundspar and is the same section found in the Pearson 36 ('72-75) and perhaps the 365 and 39. In the 10M the mast is stepped in the bilge on a steel mast step and there are corrosion problems. See the mast step page for details. In 2002 I replaced all the standing rigging on my 10M. See the New Rigging page for details.
The 10M has some heavy duty rigging. All the wire sizes are typical of a 40 footer. With 3/8" stays and 5/16" uppers any rigger will tell you it's overkill for a 33 footer. Rigging is typically speced at around a 3:1 safty factor. That means the max rigging loads are calculated and multiplied by three to pick the rigging strength. Pearsons are typically rigged with a slightly higher safety factor then average and I think the 10M is slightly higher then the typical Pearson. The 10M is probably in the 4 to 4.5 safety factor? Whatever the safety factor is the 10M has some heavy duty rigging.

RIGGING (as specefied in the 1977 parts catalog)

WIRE          Type  Diam  Length[1] pin-to-pin[2] Clevis
Headstay      1x19   3/8   43.438     45.17        5/8
Backstay      1x19   3/8   44.813     46.36        5/8
Upper Shrouds 1x19  5/16   40.771     41.96        1/2
Lowers        1x19  9/32   21.666     22.88        3/8 
Fwd Lowers    1x19  9/32   21.708     22.95        3/8 
Topping Lift  7x19    
[1] length of wire only, no turnbuckles or toggles (from Pearson parts catalog) - This will be correct only for the OEM Navtec turnbuckles
[2] As measured on hull #212 after careful rig tuning (fall 2001), pin-to-pin is chainplate to mast fitting including toggles and at pin centers.

The masthead on the 10M is integrally welded to the mast. There are four aluminum sheaves (with bronze bushings)and two crains for spinnaker halyard blocks. Some 10M's had internal halyards. Mine ('78, #212) did not but the sheaves were open below to accomidate them. The sheave dimensions are:
    overall diameter      3.75"
    diameter at groove    3.25"
    thickness             0.625"
    bushing OD (apr)      0.65"
    bushing ID            0.518" [4]
    shaft diameter        0.500" 
[4]Measurement after 24 years of service

The OEM turnbuckles on the 10M were Navtec series 500. For several years of production the screws in the turn buckles were stainless steel. Navtec issued a recall on these screws because they had a gauling corrosion problem (caused by stainless on stainless contact) with them. They were replaced with bronze screws. The screws shown in this photo ar the recalled stainless.

Shroud Tangs
These are some photos of the upper and lower shroud tangs. They are stainless steel, the fasteners are 1/4-20 x 1/2".

Bow Sprit
At least two 10M's came from the factory with an optional bow sprit. The sprit extended the J dimension from 14.2 feet to about 15.5. Hull 101 has this and a tall rig. The combination gives a total sail area of about 580 sf, 11% larger than the standard 10M.

Standing Rigging Calculations