I love Kalymnos, and I care about the future of climbing on the island. I wrote this paper in 2010 and submitted it for consideration by some of the key climbers and rebolters on Kalymnos, and I was keen for the Municipality to see it also. With news of the upcoming "bolting festival" in October-November 2013, I now publish the paper as an "open letter" to any and all interested parties.

An analysis of climbing on the island of Kalymnos with respect to new routes, the safety of fixed hardware, and route maintenance now and in the future.

Lee Cujes, 2 June 2010

"Since then, approximately 100 routes were maintained every 1-2 years (replacing corroded bolts and lower-offs). This is certainly not as frequent as we would like, and the number of routes being maintained each time is very limited compared to the grand total of routes on Kalymnos"
-- Aris Theodoropolous, Guidebook author and Kalymnos route developer

Issue: Route volume and quality

The number of new routes being established per year on Kalymnos is not decreasing. We have ~2300+ routes on Kalymnos already, with more every year. As more of the available rock is developed, we would expect to see (and encourage) fewer routes being established each year. It is important to encourage quality rather than quantity, as poor quality routes decrease the overall quality of Kalymnos climbing. Furthermore, doubling the number of routes on the island will not double the number of climbers, nor will it double revenue for the island. Nor will it even spread the impact of climbing – 90% of climbers into the future will continue to climb at only the major existing sectors, as it is these sectors which offer the highest quality climbing.

  1. Withdraw Municipality funding for new routes [edit: it is my understanding that this has happened some years ago, however corporate sponsorship of foreign route developers continues]. This was useful in the birth phase of Kalymnos climbing as it encouraged rapid development, but we are beyond this phase now. 
  2. Channel funds from all existing bolt funds that may exist on the island (example - Glaros) into rebolting, rather than new routing (ensuring climbers who donate know what they are donating for). As elsewhere in the world, motivated new routers will fund their own routes. We should see the number of new routes decrease to a more sensible level, and the quality of routes maintaining a high standard.
Hardware Issue #1: Corrosion of hardware on fixed routes

Bolts are not permanent. Especially on limestone and near the sea, we see significant corrosion within just a couple of years. This is also true in areas where the water transfer through the rock is high (i.e. anywhere with tufas e.g. Grande Grotta, Ghost Kitchen etc.) It is vital that routes are inspected and rebolted as required.

Figure 1: Unsafe, corroded anchor at Ghost Kitchen
Figure 2: Corrosion can also occur because of two 
dissimilar metals as shown here on a relatively
new route on the Vathy road sector

Figure 3: Climbers are too afraid to trust this
corroded anchor on Ghost Kitchen. They tie their
own slings and carabiner as backup

Hardware Issue #2: Wear of hardware on fixed routes
  1. Anchors in certain areas receive a lot of wear (the rope wears and cuts into the metal) and need to be replaced regularly, in some cases every year. There has recently been some analysis from Black Diamond showing how worn carabiners can cut rope.
  2. Bolts that are repeatedly fallen on can loosen in the hole and deform, especially in softer or more 'active' limestone. This can lead to failure of the bolt.
Figure 4: Dangerously worn lower-off anchor.
    Hardware Issue #3: Bolt choice

    The trubolt is the most typical bolt used on most Kalymnos routes. However, it is not the best choice.

    Figure 4: Trubolt
    1. Easy and quick to place
    2. Can be used immediately (important for equipping steep routes)
    1. Cannot be extracted from the hole to allow for clean replacement. Must be cut off using a cordless grinder and then beaten back into hole and the hole patched with epoxy and camouflaged.
    2. Because the thread sits exposed from the nut, it can foul the carabiner leading to dangerous orientation of the carabiner. There are cases where this has led to a carabiner snapping.
    3. Sideways forces on the hanger cause the nut to loosen. If the nut loosens completely, the hanger falls off and the climber has no protection. This happened to me recently during a fall. I was very lucky to escape injury. Many routes are missing hangers due to this issue.


    Figure 5: Titanium glue-in bolt.
    The best long-term solution. 

    To purchase these, visit:
    1. Corrosion
    Option 1 (mandatory): Continual assessment and rebolting with high grade (316) stainless steel as required. "316 L" is the low carbon version of 316 stainless steel and has been found to have even better corrosion resistance. Hardware is available in 316 L.

    Option 2 (possible): Thailand climbing areas have moved to titanium glue-in bolts and Hilti RE-500 epoxy glue for maximum corrosion resistance and longevity. It is suggested Kalymnos also obtain these (more expensive) bolts for use on the most corrosive sectors.

    2. Wear

    Figure 6: An anchor is replaced,
    leaving bolt remains and
    ugly scars on the rock.
    This is unnecessary, yet
    this kind of damage is
    There are several options for anchors which are replaceable without having to install a completely new anchor in a new position (this is a horrible worst case scenario, yet is the most common form here currently on Kalymnos). Glue-in threaded rod allows the same bolts to be re-used. Quickclips attached with mallions allow for the wearing component only to be replaced. The more the type of anchor set on the island is standardised, the easier ongoing replacement will become.

    3. Bolt choice
    For new routes, discontinue using trubolts. Instead, use 12mm x 75mm flush-head dynabolts of the following configuration:

    Figure 7: 12mm Flush-head dynabolt - a better choice than trubolts.

    Flush-heads offer all the advantages of the trubolt, and eliminate many of the disadvantages. They are replaceable, they have a low profile and do not snag carabiners as readily, and they do not loosen as easily as trubolts.

    Issue: Maintenance and rebolting

    Kalymnos has a reputation as a haven of ‘safe bolting’. This is important to many climbers who come here and is a reputation worth protecting.

    Rebolting is happening on the island, however the following issues have been identified:
    1. The poor quality of some of the rebolting work
    2. The fact that trubolts are being replaced with more trubolts, instead of taking the opportunity to upgrade to the best, highest-longevity solution (glue-in ringbolts)
    3. The fact that there is not enough rebolting occurring to keep up with the wear and corrosion on the ever-increasing number of routes on the island. The generally thankless task of rebolting is left to just a few motivated individuals.
    Figure 8: Seven holes drilled and not patched.
    Poets sector.
    Figure 9: Too often this is the case (we see this
    at every sector). Because trubolts cannot be
    extracted, they are left to rust. This is unsightly
    and simply lazy.

    1. Quality:
    For Kalymnos to retain its reputation and natural beauty, it is inappropriate to allow sub-standard rebolting. Trubolts must be cut, recessed and patched. Old anchors need to be removed in full. Any scars on the rock must be camoflauged. We must strive for all routes to be as perfect as they can be.

    2. Phasing out trubolts:
    We must rebolt with superior hardware. Therefore we must move to glue-in bolts. These are preferred by all climbers because they are stronger, safer, do not notch climbers’ carabiners, and allow for rope to be directly threaded to allow for retreat from any point on the route if required. They do require more skill to place, but most importantly, they will last much longer in this environment than any form of expansion bolt. In this seaside environment, a minimum specification of 316 or 316 L stainless steel should be mandated, with titanium preferred as the best possible option (see: Thailand titanium rebolting article).

    Figure 10: 316 stainless glue-in ringbolt, correctly recessed.
    3. Establishment of a centralised hub for bolting/rebolting
    1. Online and offline method for climbers to report “bad bolts/routes” for inspection.
    2. Online “to-do” list with routes and sectors scheduled for rebolting/maintenance.
    3. Online and offline methods for visiting climbers to donate money to the rebolting initiative. If even a small fraction of the money entering the Kalymnian economy by climbers went towards rebolting, this would ensure the initiative could be appropriately funded.
    4. Online database of rebolted routes to show how the money is being spent, exactly what hardware is used etc. (Example of such a database)
      4. Dedicated focus on ongoing maintenance and rebolting
      One or more rebolting specialists must be engaged by the Municipality (or corporate sponsors) to conduct the required work every year, on an ongoing basis. The Municipality has spent a great deal of money establishing Kalymnos as one of the world’s premier climbing destinations (by investing in new routes), however we must continue to maintain and protect that investment in the long term. This requires an ongoing financial commitment.


      I would like to offer thanks and gratitude to those climbers such as Aris Theodoropolous and Simon Montmory who have contributed serious time and effort to rebolting on Kalymnos. This article is not a criticism, rather a call to action.

      I believe a combination of both local commitment (Municipality), corporate commitment (sponsored initiatives) and commitment from climbers themselves (via donations) will provide the assistance necessary to fund the recommendations in this article.

      As the world's premier sport climbing destination, Kalymnos deserves ongoing care and ongoing investment.

      Other resources:


      Dave said...

      That's well said Lee. The investment should now be going into maintenance.

      cragrat said...

      Re The 12mm Dyna bolts - make sure people know that the sleeve (12mm) needs to fit into the bolt hanger hole and thus you need 12mm hangers not 10mm - something I have seen before.