Bobbins

Bobbins are mechanical descenders where the rope path follows the S-shaped path shown in the figure. The braking surface typically consists of two non-rotating bollards fixed to a side plate, with a second pivoting side plate provided to keep the rope from jumping off the other end of the bollards. A third (usually smaller) bollard may be provided. The seat maillon usually attaches to holes in extensions of the two side plates; these holes are aligned when the side plates pivot to the closed position.

Some bobbins have a mechanism that applies additional braking force if the rappeller releases or squeezes (depending on the design) a handle on the bobbin. Plain bobbins, the subject of this page, have no such mechanism. I divide the bobbins with such mechanisms into these groups:

1. Stop Bobbins, where the main upper bollard is fixed to the rear plate, the main lower bollard is fixed to a rotating lever that moves in one direction to stop and the other for descending,

2. Double-Stop Bobbins, where the main upper bollard is fixed to the rear plate, the main lower bollard is fixed to a rotating lever that moves in either direction to stop and to the center for descending, and

3. Near Bobbins, where the two main bollards are attached to a rotating lever. These may have a double stop feature, and attachments to provide for a double stop are available for most of those that do not.

Bobbins are quite popular among European cavers, but then again, they all seem to use almost exactly the same system. This has advantages, but stifles creativity. I've used bobbins as my short-drop device, but they really don't have enough friction for my weight (I'm 1.91 m., 88 kg.), especially when I'm carrying a heavy load. They should work better for a 50 to 60 kg lightweight.

ID	Device ↓	Description	Acquired	Weight ↓	Height ↓	Width ↓	Thickness ↓	Std. volume ↓
430	Austrian	Rod frame, solid spools, lower spool cut & pivots on frame, noncommercial	Peter Ludwig, 1991	195	143	45	40	257
450	Cascade (Каскад)	Bent frame, solid spools, aux. bar, wire gate	Vladimir Kisseljov & Ilia Alexandrov,1994	353	195	45	32	281
2583	Climbing Technology Acles DX	Bent frame, solid spools, aux. bar, stamped gate. Right-hand version	Amazon.com, 2020	244	197	56	29	316
3358	Dresler Single	Bent frame, unfinished, solid spools, stamped gate	Raúl Macia Sanchez, 2023	227	193	44	27	232
3161	Dresler Double	Bent frame, unfinished, 2 groove upper spool, 1-groove lower spool, stamped gate	Josep Guarro, 2022	321	197	45	40	353
3241	Emilsa	Bent frame, unfinished, solid spools, no gate	Raúl Macia Sanchez, 2022	213	194	45	26	221
1471	John Woods	Bent frame, unfinished, Petzl spools, sheet metal gate	John Woods, 2015	269	207	47	36	351
2590	Kailas Alfa	Stamped frame, solid spools, aux. top bar, aux. arm /w bar, stamped gate	Kailas, 2021	281	197	60	34	407
2416	Key Chain Bobbin	Bent frame, solid spools. UNSAFE! Decorative use only.	Bob Thrun Collection, 2017	17	56	13	12	9
434 2421	Kong-Bonaiti Doble	Bent frame, solid spools, plastic gate	Inner Mountain Outfitters, 1994 Bob Thrun Collection, 2017	269	193	55	32	340
951	Kong Banana	Curved bent frame, solid spools, aux bar, stamped gate	Inner Mountain Outfitters, 2004	233	193	55	30	316
1465	Orcus	Bent frame, unfinished, solid spools	Ondřej Belica, 2015	248	187	46	37	318
3108	Orion-Alp Gurney (Орион-Альп Каталка)	Bent painted frame, solid spools, stamped gate	Artyom Babin (Артём Бабин), 2021	253	213	46	32	310
1207	Petzl, double rope, Version A	Bent frame, unfinished, 2 groove upper spool, 1-groove lower spool, stamped gate	Albéric Sibille, 2009	305	197	45	41	359
439 1232 2418	Petzl, double rope, Version B	Bent frame, unfinished, 2 groove upper spool, 1-groove lower spool	Al Fincham, 1981 Susan Wooly, 2009 Bob Thrun Collection, 2017	311	194	45	41	358
440	Petzl, double rope, Version C	Bent frame, unfinished, 2 groove spools, stamped gate	Al Fincham, 1981	324	191	45	41	352
1206	Petzl Simple, Version A	Bent frame, unfinished, solid spools, stamped gate	Albéric Sibille, 2009	214	193	44	31	258
1220	Petzl Simple, Version B	Bent frame, unfinished, solid spools, stamped gate	Mariana Oliveira, 2009	214	193	45	26	226
2317	Petzl Simple, Version C	Bent frame, unfinished, solid spools	Bob Thrun Collection, 2017	233	192	45	31	266
441	Petzl Simple, Version D	Bent frame, unfinished, solid spools	Speleoshoppe, 1979	220	187	45	31	261
442 1185	Petzl Simple, Version E	Bent frame, unfinished, solid spools, stamped gate	Speleoshoppe, 1979 Hawill’s Ltd., 2008	240	182	45	31	254
1242	Petzl Simple, Version F	Bent frame, soft anodized solid spools, stamped gate	Francois Gelinas, 2009	236	189	45	31	261
444	Petzl Simple, Version G	Bent frame, solid spools, aux. bar, stamped gate	John E. Weinel, Inc., ~1987	248	195	45	32	281
443 2419	Petzl Simple, Version H	Stamped frame, solid spools, aux. bar, stamped gate	1990 Bob Thrun Collection, 2017	248	195	45	32	281
2496	Petzl Simple, Version I	Stamped frame, solid spools, aux. bar, stamped gate	On Rope 1, 2018	242	196	45	32	281
1010	Petzl Simple, Version J	Stamped frame, solid spools, aux. bar, plastic gate	Inner Mountain Outfitters, 2006	237	197	42	32	267
2527	Petzl Simple, Version K	Stamped frame, solid spools, aux. bar, plastic gate	Petzl America, 2019	251	197	47	32	292
1469	RB	Bent frame, unfinished, 2 groove upper spool, 1-groove lower spool	Olivier Peron Caillet, 2015	313	199	45	43	383
1160	Repetto Bis-Bang	Stamped frame, large Al & small steel solid spools, aux. bar, stamped gate, double rope	Expé-Spelemat, 2008	247	177	56	41	407
2566	Repetto Spider (Left)	Bent frame, solid spools, aux. bar, stamped gate. Left-hand version.	John Fioroni, The Cave Exploration Society Inc., 2020	247	197	52	29	297
929	Repetto Spider (Right)	Bent frame, solid spools, aux. bar, stamped gate. Right-hand version.	Inner Mountain Outfitters, 2003	251	197	52	29	297
2415	Rocksport Buggery Box	Fixed Al Plate & bent Al cover, bronze bollards	Bob Thrun Collection, 2017	314	155	49	30	233
4011	Unknown	Symmetrical double-ended, Al frame & spools, hex bolts, washers & wing nuts	Collectables from Maine, 2024	436	218	50	56	610
1163	Unknown "S"	Bent frame, solid cylindrical spools, noncommercial	Bill Boehle, 2008	245	203	38	38	298